important observations upon the electric character of the aurora,
the experiments carried on by him in the mountains of Finland being
thus described: “We surrounded the peak of a mountain with copper
wire, pointed at intervals with tin nibs. We next charged the wire
with electricity, and nearly every night during our stay produced a
yellowish white light on the tin points, in which the spectroscope
analysis revealed the greenish yellow rays so characteristic of the
aurora borealis. On the peak of Pietarintumturi we were especially
successful, an auroral ray making its appearance directly over and
about 150 yards above the copper coil.”
A complete list of all auroras appearing prior to 1754 is to be found
in Jean Jacques d’Ortons de Mairan’s, Paris, 1731, “Traité Physique de
l’Aurore Boréale,” and a catalogue of auroræ observed, 1800–1877, has
been made up by M. Zenger (_Sci. Am. Supp._, p. 10915). One of the most
interesting displays is known as the _purple aurora_, alluded to in the
Annals of Clan-mac-noise as having appeared A.D. 688 (Biot “Note sur la
direction,” etc., _Comptes Rendus_, Tome XIX for 1844, p. 822). Between
September 19, 1838, and April 8, 1839, Lottin, Bravais, Lilliehöök
and Siljeström observed 160 auroras at Bossekop (69° 58’ N. lat.)
in Finmark and at Jupvig (70° 6’ N. lat.); they were most frequent
during the period the sun remained below the horizon, that is, from
November 17 to January 25. During this night of 70 times 24 hours there
were 64 auroras visible (_Comptes Rendus_, Tome X. p. 289; Martin,
“Météorologie,” 1843, p. 453; Argelander, in the “Vorträgen geh. in der
Königsberg Gesellschaft,” Bd. I. s. 259).
A Finnish physicist, named S. Lenström, who had been attached to the
Nordenskjold Polar Expedition of 1868, visited Lapland in 1871, and,
after a series of important observations, constructed an apparatus that
permitted him to “artificially reproduce the light of the aurora.” The
intensity of this light is so great at times that Lowenörn perceived
the coruscations in bright sunshine on the 29th of January, 1786, and
Parry saw the aurora throughout the day during the voyage of 1821–1823.
The height of the aurora has been variously estimated, but it is seldom
found to be less than forty-five miles above the surface of the earth.
Father Boscovich estimated at 825 miles the height of the one observed
by the Marquis of Poleni on the 16th of December, 1737. The extent of
the aurora, according to Dalton, has been known to cover an area of
7000 or 8000 square miles.
REFERENCES.--“Mem. de Turin,” An. 1784–5, Vol. I. part ii. pp.
328, 338; Young, “Lectures,” Vol. I. pp. 687, 716; Herschel,
“Prelim. Discourse,” pp. 93, 329, 330; _Phil. Trans._, 1753,
p. 350; Müller’s “Kosmischen Physik”; Noad, “Manual,” pp.
225–237; also all the references at pp. 187–196, Vol. I of
Humboldt’s “Cosmos,” Bohn, London, 1849, as well as in Ronalds’
“Catalogue,” pp. 23–24; Mairan, at Vol. X. p. 961, “Dict.
Univ.,” and Vol. XXVI. p. 161, of the “Biog. Universelle”;
_Trans. Cambridge Phil. Soc._, Vol. I; “Isis Unveiled,” Vol. I.
pp. 417, 418.
See likewise the “Pharsalia” of Marcus Annæus Lucanus,
translated by J. Krais, I. pp. 518–527; Plutarchus, “De facie in
orbe lunæ,” cap. 26; the “Annals” of Caius Cornelius Tacitus,
Germania, XLV. 1st ed., Venice, 1470; “Das Polarlicht,” H.
Fritz, Leipzig, 1881, pp. 4–6, 332; Mairan’s “Traité Physique,”
etc., 1731, pp. 179–181; Grégoire du Tour, _Lumière Electrique_,
1882, Vol. VII. p. 389; Elias Loomis, “The Aurora Borealis,”
etc., p. 220 of the Reports of Smiths. Inst., 1865; A. M. Mayer,
“Observations,” etc., _Amer. Jour. of Sc._, February 1871; “A
copy of the Catalogue of Aurorae Boreales observed in Norway
from the earliest times to June 1878” (“Nature,” December
4, 1902, p. 112); “La cause de l’aurore boréale,” Claudius
Arrhenius, in the _Revue Générale des Sciences_ for January 30,
1902, pp. 65–76; “Les Années Météores,” in “Le Cosmos,” Paris,
May 25, 1889, etc.; “Terrestrial Magnetism,” March 1898, p.
7 for Chronological Summary of Authors re Aurora; Rev. Jas.
Farquharson in “Abstracts of Sc. Papers Roy. Soc.,” Vol. II.
p. 391; Wm. Dobbie, _Phil. Mag._, Vol. LXI for 1823, p. 252;
W. Derham, for description of Auroras (in _Phil. Trans._ for
1728, p. 453); see, for Boscovitch, “Journal des Savants,”
February 1864; “Journal des Savants,” for August 1820; C.
H. Wilkinson, “Elements,” 1804; Vol. II. p. 279 and note;
Calogera’s “Raccolta,” XVII. 47, _Proc. of the Royal Soc. of
Edinburgh_ for the observations of J. A. Brown and others on
the aurora; F. C. Meyer, De luce boreali, 1726; Poggendorff, I.
135; Sturgeon, “Sc. Res.” 4th Sec. p. 489; _Phil. Trans._, Vol.
XXXVIII. p. 243; Vol. XLVI. p. 499; F. Zöllner’s paper in “L.
E. and D. Philos. Mag.,” for May and July, 1872; C. A. Young,
_Amer. Jour. of Sc_., Vol. III., 3rd s., p. 69; Baron Karl Von
Reichenbach’s “Physico-Physiological Researches,” trans. of Dr.
John Ashburner, London, 1851, pp. 5–36, also pp. 445, etc.,
of the translation of Dr. W. Gregory, London, 1850; J. H. Van
Swinden, “Recueil de Mémoires,” etc., La Haye, 1784, Vol. III.
p. 187, etc.; J. E. B. Wiedeburg, “Beobachtungen und Muth.,”
etc., 1771; G. W. Krafft, “Observ. Meteor,” etc., in _Novi Com.
Acad. Petrop._, Vol. V. p. 400; Giuseppe Toaldo, “Descrizione,”
etc., in _Saggi ... Accad. di Padova_, Vol. I. p. 178; Louis
Cotte, “Table of Auroræ, Observed ... 1768–1779,” Paris, 1783;
_Journal de Physique_ for 1775; _Recueil de Mem. de l’Acad. des
Sciences_ for 1769; A. S. Conti, “Rifflessioni sull’ Aurora
Boreale.”[48]
For _Auguste Arthur De la Rive_, consult “Bibl. Britan.,” Vol.
XVI, N.S., 1821, p. 201, likewise the “Annales de Chimie et de
Physique,” _Phil. Mag._, _Phil. Trans._, _Comptes Rendus_, more
especially, as well as the “Bibl. Univ.” and the “Mem. de la
Soc. de Genève,” at which latter place he was born in 1801.
For _Jean Jacques d’Ortons de Mairan_, consult “Mém. de Paris”
for the years 1726, 1731–1734, 1747, 1751, also abridgments of
the _Phil. Trans._ by Hutton, Vol. VII. p. 637, and by Baddam,
1745 ed., Vol. IX. pp. 490–497.
For _W. Derham_ (1657–1735) consult also “Nouv. Biog. Gen.”
(Hœfer), Vol. XIII. p. 712; the _Phil. Trans._ unabridged, Vol.
XXIV. for 1704–1705, pp. 2136–2138; Vol. XXXVI. pp. 137, 204,
also the following abridgments: Hutton, Vol. V. pp. 258–263;
Hy. Jones, Vol. IV. part ii. pp. 290–291; Baddam, Vol. IV. pp.
473–478. In the last-named volume is thus given an account
of Mr. Derham’s experiments: “He shows (_Phil. Trans._, No.
303, p. 2136) that, having consulted what others had writ of
magnets, he finds in Grimaldi’s _De Lumine et colore_ that both
he and M. De la Hire (_Phil. Trans._, No. 188) had hit upon
the same discovery before him.” Mr. Derham also alludes, more
particularly, to the observations of Ridley, Barlow and Dr.
Gilbert.
For _Claudius--Claes--Arrhenius_ (1627–1694) Swedish scientist,
professor at the Upsal University, consult “La Grande Encycl.,”
Vol. III. p. 1107; “Dict. Biog. Suédois,” Vol. XXII. pp. 385–389.
For _John Wallis_, the celebrated English mathematician
(1616–1703), in addition to the above-named _Phil. Trans._,
Vol. XXIII for 1702–1703, p. 1106, consult _Phil. Trans._, Vol.
XII for 1677, No. 135, pp. 863–866 (meteors), also the abridged
editions as follows: Hutton, Vol. IV. pp. 196, 639, 655; Hy.
Jones, Vol. IV. part ii. p. 286; Baddam, London, 1739, Vol. III.
p. 228 and Vol. IV. pp. 100–104 (mariner’s compass); “Nouv.
Biog. Gen.” (Hœfer), Vol. XLVI. p. 530.
AURORA AUSTRALIS, OR SOUTHERN POLAR LIGHT
The earliest account of this phenomenon was given by Don Antonio de
Ulloa, as will be seen under date A.D. 1735–1746.
REFERENCES.--W. L. Krafft, “Observation,” etc., in _Acta Acad.
Petropol._ for 1778, Part I. Hist., p. 45; _Phil. Trans._, XLI.
pp. 840, 843; XLVI. pp. 319, 345; Chr. Hansteen, “On the Polar
Lights,” London, 1827.
ZODIACAL LIGHT
This phenomenon, from its occasional faint resemblance to and
association with the auroras, would seem to deserve mention here,
though none of the conjectures formed, more particularly by Cassini,
Euler, Mairan, Kepler, Laplace, Fatio de Duiller, Schubert, Poisson,
Olmsted, Biot, Herschel, Delambre, Olbers or Sir Wm. Thomson attribute
to it any electric or magnetic origin.
In the _Report of the Proceedings of the Reale Istituto Lombardo_,
1876, however, appears the account of many observations confirmed by
M. Serpieri which “demand absolutely” the conclusion that the zodiacal
light “is an electrical aurora preceding and following the sun round
the earth.”
Angstrom asserted that he observed the auroral line in the spectrum of
the zodiacal light, and Lewis saw the latter during the aurora of May
2, 1877. Humboldt, who observed it (“Cosmos,” 1849, Vol. I. p. 126) in
the Andes at an elevation of 13,000 to 15,000 feet, as well as on “the
boundless grassy plains, the Llanos of Venezuela, and on the seashore,
beneath the ever-clear sky of Cumana,” believes it to be caused by “a
very compressed annulus of nebulous matter, revolving freely in space
between the orbits of Venus and Mars.” In this connection he refers to
Arago in the _Annuaire_ for 1832, p. 246, and to a letter published
in _Comptes Rendus_, XVI, 1843, p. 687, from which the following is
extracted: “Several physical facts appear to indicate that, in a
mechanical separation of matter into its smallest particles, if the
mass be very small in relation to the surface, the electrical tension
may increase sufficiently for the production of light and heat.”
In Chambers’ “Descript. Astronomy,” p. 257, the historian Nicephorus
is credited with first calling attention to the existence of this
phenomenon, to which Giovanni Domenico Cassini gave the name of
Zodiacal Light, after determining its relations in space during the
year 1683 (_Mém. de l’Académie_, 1730, Tome VIII. pp. 188 and 276),
but to Childrey belongs the credit of having given to Europe the
first explicit description of this phenomenon at p. 183 of his 1661
“Britannia Baconica.”
REFERENCES.--Sturgeon’s _Annals_, etc., Vol. II. pp. 140–142;
Prof. C. W. Prichett’s paper in _Sci. Am. Supp._, No. 126, p.
2008, and the conclusions reached by Herr Gronemann (_Archives
Néerlandaises_) in _Sci. Am. Supp._, No. 327, p. 5221; Whewell,
“Hist. of the Ind. Sciences,” 1859, Vol. I. p. 531, and Vol. II.
p. 609; Tyndall, “Heat as a Mode of Motion,” 1873, pp. 57, 58,
497, 498; J. F. J. Schmidt, “Das Zodiacallicht,” Braunschweig,
1856; the very interesting abstract given in “The Journal of
the Brit. Assoc.,” Vol. XII. No. 5, of paper read by Rev. J.
T. W. Claridge, F.R.S., Jan. 9, 1902; Houzeau et Lancaster,
“Bibl. Générale,” Vol. II. 1882, pp. 763–771; “Pr. Roy. Soc. of
Edin.,” XX. pt. 3; C. Wilkes, “Theory of Zod. Light,” Philad.,
1857; _Phil. Trans._, Vol. XXXVIII. p. 249; “Cosmos,” 1849,
Vol. I. pp. 126–134; “Anc. Mém. de Paris,” I, VIII and X; J.
J. de Mairan, Paris, 1733; “U. S. Japan Expedition,” Vol. III,
Washington, 1856.
=A.D. 1684.=--Hooke (Dr. Robert), English natural philosopher
(1635–1703), who, in 1677, had succeeded Oldenburg as Secretary to the
Royal Society, gives the earliest well-defined plan of telegraphic
transmission, in a paper addressed to the Royal Society “showing a way
how to communicate one’s mind at great distances ... 40, 100, 120,
etc., miles ... in as short a time almost as a man could write what
he would have sent.” His apparatus consisted of an elevated framework
supporting an open screen, behind which were suspended as many wooden
devices, or symbols, such as circles, squares, triangles, etc., as
there were letters in the alphabet. In the daytime these devices were
drawn up by a rope behind the screen and made visible in the open
space, while during the night use was made of torches, lanterns or
lights.
Hooke also showed, in 1684, that iron and steel rods can be permanently
magnetized by strongly heating them and by rapidly cooling them in the
magnetic meridian (“Enc. Brit.” 1857, Vol. XIV. p. 3).
But, what is still more singular, he had, even previous to the
above-named date (_i. e._ in 1667), alluded to the possibility
of telephoning, that is, communicating sound through a wire. He thus
expresses himself: “And as glasses have highly promoted our seeing,
so it is not improbable that there may be found many mechanical
inventions to improve our other senses--of hearing, smelling, tasting,
touching.... ’Tis not impossible to hear a whisper a furlong’s
distance, it having been already done; and perhaps the nature of the
thing would not make it more impossible though that furlong should be
ten times multiplied. And though some famous authors have affirmed
it impossible to hear through the thinnest plates of Muscovy glass,
I know a way by which it is easy to hear one speak through a wall
a yard thick. It has not been examined how far acoustics may be
improved, nor what other ways there may be of quickening our hearing,
or conveying sound through other bodies than the air, for that is not
the only medium. I can assure the reader that I have, by the help of a
distended wire, propagated the sound to a very considerable distance
in an instant, or with as seemingly quick a motion as that of light,
at least, incomparably swifter than that which at the same time was
propagated through the air; and this not only in a straight line, or
direct, but in one bended in many angles.”
REFERENCES.--Hooke’s entire paper in Derham’s “Phil. Exp. and
Obs.” for 1726, pp. 142–150; _Phil. Trans_, for 1684; for his
observations on atmospheric electricity consult Houzeau et
Lancaster, “Bibl. Gén.,” Vol. II. p. 166; “Journal des Savants”
for April 1846; “The Posthumous Works of Robert Hooke,” London,
1705, p. 424; “Revue Scientifique,” Mars 15, 1902, p. 351;
for a complete list of all his works, consult Ward’s “Lives
of the Gresham Professors”; for description of his telegraph
and reference to Amontons, etc., see _Phil. Mag._, Vol. I. pp.
312–316.
=A.D. 1684.=--Sturmy’s “Mariner’s Magazine” for this year, of
which a copy can be seen in the library of the British Museum, contains
an account of the deviation of the compass and its tendency to give
misleading directions on account of local attraction.
REFERENCES.--_Chambers’ Journal_, Vol. III. No. 60 for Feb.
24, 1855, p. 132, and Vol. XII. No. 300 for Oct. 1, 1859, p.
246; Capt. Sam. Sturmy’s “Magn. Virtues and Tides,” in _Phil.
Trans._, No. 57, p. 726, or “Memoirs of the Roy. Soc.,” Vol.
I. p. 134; _Phil. Trans._, abridgments: by Hutton, Vol. II. p.
560, and by Lowthorp, Vol. II. p. 609; “Journal des Sçavans” for
1683, Vol. XI. pp. 267–293.
=A.D. 1684.=--In the “Essayes of Natural Experiments made in the
Accademia del Cimento” (Englished by Richard Waller), London, 1684,
by direction of the Royal Society, there are given, respectively at
pp. 53, 123 and 128–132, accounts of the operation of the magnet _in
vacuo_, details of several magnetical experiments and experiments
touching amber as well as other electrical bodies.
=A.D. 1686.=--Maimbourg (Louis), French historian, relates this
instance of the employment of the magnet at Chap. VI of the Rev. W.
Webster’s translation of his “Histoire de l’Arianisme”: “Whilst Valens
(the Roman emperor) was at Antioch ... several pagans of distinction,
with the philosophers ... not being able to bear that the empire
should continue in the hands of the Christians, consulted privately
the demons ... in order to know the destiny of the emperor and who
should be his successor.... For this purpose they made a three-footed
stool ... upon which, having laid a basin of divers metals, they placed
the twenty-four letters of the alphabet around it; then one of these
philosophers, who was a magician ... holding in one hand vervain and in
the other a ring which hung at the end of a small thread, pronounced
... conjurations ... at which the three-footed stool turning around and
the ring moving of itself, and turning from one side to the other over
the letters, it caused them to fall upon the table ... which foretold
them ... that the Furies were waiting for the emperor at Mimas; ...
after which the enchanted ring, turning about again over the letters in
order to express the name of him who should succeed the emperor, formed
first of all these capital letters, T H E O. After adding a D, to form
T H E O D, the ring stopped, and was not seen to move any more, at
which one of the assistants cried out ... ‘Theodorus is the person whom
the gods appoint for our emperor’” (“History of Christianity,” by the
Rev. Henry Hart Milman, London, 1840, Vol. III. p. 120).
Maimbourg’s biography is given at p. 58, Vol. IV. of the “English
Encyclopædia.”
=A.D. 1692.=--Dr. Le Lorrain de Vallemont relates, in “Description
de l’Aimant,” etc., which he published at Paris, that, after a very
severe wind and rain storm during the month of October 1690, the new
steeple of the Church of Notre Dame de Chartres was found to be so
seriously injured as to necessitate demolition. It was then observed
that the iron cross was covered with a heavy coating of rust, which
latter proved to be so highly magnetic that a special report upon it
was made in the “Journal des Sçavans” by M. de la Hire, December 3,
1691, at the request of Giovanni Dom. Cassini, and of other members of
the French Royal Academy.
REFERENCES.--“Journal des Sçavans,” Vols. XX, 1692, pp. 357–364
and Vol. XXXV, 1707, pp. 493–494 for additional accounts of
the Church of N. Dame de Chartres by M. de la Hire and M. de
Vallemont, and for a review of M. de Vallemont’s work, of which
latter pp. 4, 30, 66, 74, 89 to 90 merit special attention.
A.D. 1693.--Gregory (David), an eminent mathematician, who, in
1691, had been made Savilian Professor of Astronomy in Oxford mainly
through the influence of Newton and Flamsteed, communicates the result
of his observations on the laws of magnetic action.
REFERENCES.--Noad, “Manual of Electricity,” 1859, p. 525, _Phil.
Trans._, Vols. XVIII-XXV; “Biog. Générale,” Vol. XXI. p. 902;
Ninth “Britannica,” Vol. XI. p. 182; J. J. Fahie, “A History of
El. Tel. to the year 1837,” London, 1884, p. 24.
=A.D. 1693.=--In the first volume (Letter IV. pp. 25–28) of the
“Memoirs for the Ingenious ...” by J. de la Crosse, are given accounts
of several “New experiments on the loadstone; of a needle touch’d with
it, and plac’d directly over the needle of a compass; of two Mariner’s
Needles hang’d freely over one another, at several distances; of a
touch’d steel-ring. Reasons of these experiments. The earth magnetical.”
In explanation of all this, M. de la Hire supposes “that the mass of
the earth is a great loadstone, which directs the poles of the same
name in all the loadstones and touch’d needles, towards the same place
of the earth; so that the two hang’d needles do but remove from this
natural position by the particular force they have of driving away
each other’s poles of the same name; which force, in a certain degree,
is not sufficient to overcome the power of the great loadstone of the
earth.”
An account of M. P. de la Hire’s “new sort of a magnetical compass” had
already appeared in the _Phil. Trans._ for 1686–1687, Vol. XVI.
No. 188, p. 344.
REFERENCES.--For De la Hire, the following abridgments of the
_Phil. Trans._: Lowthorp, London, 1722, Vol. II. pp. 620–622;
Baddam, London, 1739, Vol. IV. pp. 473–478; Hutton, London,
1809, Vol. III. p. 381; also “The Phil. Hist. and Mem. of the
Roy. Acad. at Paris,” by Martyn and Chambers, London, 1742, Vol.
II. pp. 273–277; Vol. V. pp. 272–282 and the “Table Alphab. ...
Acad. Royale,” by M. Godin, Paris, Vol. II. p. 16 and Vol. X.
pp. 164 and 734.
=A.D. 1696.=--Zahn (F. Joannes), prebendary of the Prémontrés
Order at Celle near Wurtzburg and provost of the convent of Niederzell,
celebrated for his philosophical and mathematical studies, publishes
his highly valued “Specula physico-mathematico-historica-notabilium ac
mirabilium sciendorum ...” throughout the three folio volumes of which
he treats extensively of the wonders of the entire universe.
In his tabulated list of the origin and properties of all the different
known gems and stones (Vol. II. chap. vii. p. 55), he states that
the loadstone, first discovered at Magnesia in Lydia (Caria--on the
Mæander) is heavy, very well shaped, and of a dark colour verging upon
blue. The marvellous properties of gems and stones are detailed at pp.
59–73 of the same volume, the fifth paragraph of Chap. VIII treating of
the loadstone’s many virtues and admirable qualities, as exemplified
in the writings of Guilielmus Gilbertus, Nicolaus Zucchius, Nicolaus
Cabæus, Athanasius Kircherus, Eusebius Nierembergius, Laurentius
Forerus, Hieronymus Dandinus, Jacobus Grandamicus, Ludovicus Alcazar,
Claudius Franciscus Milliet de Chales, as well as of many others.
REFERENCES.--Michaud, “Biog. Univ.,” Vol. XLV. p. 340; Dr. John
Thomas, “Universal Pron. Dict.,” 1886, p. 2514; Brunet, “Manuel
du Libraire,” Vol. V. p. 1519.
=A.D. 1700.=--Bernoulli (John I), son of Nicolas, the founder of
the celebrated family of that name, improves upon Picard’s discovery of
the electrical appearance of the barometer, made A.D. 1675,
by devising a mercurial phosphorus or mercury shining _in vacuo_
(“Diss. Physica de Mercurio Lucente,” etc., Basel, 1719). This procured
the favourable notice of King Frederick I, of Prussia, who rewarded
him with a medal. John Bernoulli I (1667–1748) was a member of nearly
every learned society of Europe and “one of the first mathematicians
of a mathematical age.” His exceedingly valuable memoirs, found in all
the scientific transactions of the day, were first collected in their
entirety during the year 1742, by Cramer, Professor of Mathematics, and
published at Lausanne and Geneva.
“Is it not surprising,” remarks Prof. Robison, in his able article on
“Dynamics” (Eighth “Britannica,” Vol. VIII. p. 363), “that, twenty-five
years after the publication of Newton’s ‘Principia,’ a mathematician on
the Continent should publish a solution in the Memoirs of the French
Academy, and boast that he had given the first demonstration of it?
Yet, John Bernoulli did this in 1710. Is it not more remarkable that
this should be precisely the solution given by Newton, beginning from
the same theorem, the 40th I., Prin., following Newton in every step
and using the same subsidiary lines? Yet, so it is.” This was five
years after he had accepted (1705) the chair of mathematics made vacant
by the death of his brother, James I.
BERNOULLI FAMILY
The Bernoulli family is as well known in the history of mathematics, by
the distinguished services of eight of its members, as is the Cassini
family through the successes achieved by four of its representatives in
the development of astronomical studies.
Daniel Bernoulli (1700–1782), second son of John I, constructed a
dipping needle, which is described on p. 85 of the Eighth “Britannica,”
Vol. XIV, and with which he observed the dip to diminish half a degree
during an earthquake in the year 1767. Before Daniel was twenty-four
years old he had declined the Presidency of the Academy of Sciences
at Genoa, and, at the age of twenty-five, was appointed Professor of
Mathematics at St. Petersburg.
John Bernoulli II (1710–1790), youngest of the three sons of John I,
gained three prizes from the French Academy of Sciences for Memoirs on
the Capstan, on the Propagation of Light and on the Magnet.
John Bernoulli III (1744–1807), grandson of John I, took the degree of
Doctor of Philosophy at the age of thirteen, and, when nineteen years
old, was appointed Astronomer Royal of Berlin. He published several
volumes of travels, in one of which he relates (A. L. Ternant, “Le
Télégraphe,” 1881, p. 32) that he saw, in the last-named city, an
instrument constructed of five bells, with which all letters of the
alphabet could be expressed.
James Bernoulli I (1654–1705), brother of John I, while at London, was
introduced into the philosophical meetings of Boyle, Hooke, Edward
Stillingfleet and other learned and scientific men. He opened, in
1682, the _Collegium Experimentale Physico-Mechanicum_ for public
instruction, but his lasting fame dates from the year 1684, when the
great Von Leibnitz published his treatise “De Gravitate Ætheris.” Three
years later, in 1687, James occupied the mathematical chair of the
University of Basel, made vacant by the death of the learned Megerlin.
REFERENCES.--Whewell, “Hist. of the Inductive Sciences,” 1859,
Vol. I. pp. 358–366, 375–380, 393, 430, and Vol. II. pp. 32–39,
42; “Hist. de l’Acad. Royale des Sciences,” 1700–1707; Edin.
“Encycl.,” 1813, Vol. III. pp. 464–470; “Med. Library and
Historical Journal,” New York, 1903, Vol. I. pp. 270–277.
For Bernoulli family see “Histoire des Sc. Math. et Phys.,”
Maxim. Marie, Paris, 1888, Vols. VII-XI; “Geschichte der
Mathemathik,” Moritz Canton, Leipzig, 1898, Vol. III. pp.
207–261; “Histoire Générale des Mathématiques,” Chas. Bossut,
Paris, 1810, Vol. II. s. 2, as at table, p. 512. See the family
tree in “Eng. Cycl.,” Vol. VI. p. 972, and all the Bernoullis at
p. 84 of Vol. II, Houzeau et Lancaster’s “Bibl. Gén.,” 1882.
=A.D. 1700.=--Morgagni (Giovanni Battista), while practising
medicine at Bologna and at Venice, uses the magnet to remove particles
of iron which had accidentally fallen into the eyes, exactly in the
same manner as Kirkringius and Fabricius Hildanus had done before him.
REFERENCES.--Maunder’s “Biog. Treasury”; also Beckmann’s
“History of Inventions,” Vol. I. p. 44, and biography in
Larousse, Vol. XI, as well as in Vol. XVI of the Ninth
“Britannica.”
=A.D. 1700.=--Duverney (Joseph Guichard), an eminent French anatomist,
knew at this date that the limbs of a frog are convulsed by the
electric current (as shown in the “Histoire de l’Académie des
Sciences,” 1700, p. 40, and 1742, vol. I. p. 187), and the Italian
physician L. Marco Antonio Caldani, assistant to Morgagni, alludes to
the “revival of frogs by electrical discharges.”
REFERENCES.--“Ency. Metrop.,” Vol. IV. p. 220; Highton’s “Elect.
Tel.”; Fahie, “Hist. of Elec. Tel.,” pp. 175 and 176 and notes;
Knight’s “Mech. Dict.,” Vol. II. p. 936; G. H. Browne, London,
1704, and in “Phil. Mag.,” Vol. XVIII. p. 285, also note p. 83
of Ronalds’ “Catalogue.”
=A.D. 1701–1702.=--Le Brun (Pierre), French theologian (1661–1729),
publishes his “Histoire Critique des Pratiques Superstitieuses,”
wherein he makes mention (Vol. I. p. 294) of the possibility of
transmitting intelligence in the manner indicated by the Jesuit
Leurechon.
He is also the author of “Lettres qui découvrent l’illusion des
philosophes sur la baguette divinatoire,” Paris, 1693 (Larousse’s
“Dictionnaire,” Tome X. p. 292).
=A.D. 1702.=--Bion (Nicolas), French engineer and manufacturer of
mathematical and astronomical instruments (1652–1733), is the author
of “Usage des Astrolabes,” which was shortly after followed by his
well-known “Traité de la construction et des principaux usages des
instruments de mathématique.” In the preparation of the last named,
which was translated into German (Leipzig, 1713, Nuremberg, 1721) as
well as into English (London, 1723, 1738), Bion admits the assistance
afforded him by Lahire, Cassini and Delisle the younger.
The whole of Book VII (pp. 267–290) of the “Traité,” is devoted to the
description of instruments employed in navigation, the compass and
the astrolabe in particular, with instructions for ascertaining the
declination and variation.
Bion is also the author of “L’Usage des Globes Célestes et Terrestres
et des sphères suivant les differents systèmes du monde,” Amsterdam,
1700. Much of the matter, however, is said to have been copied by Bion
from Pierre Polinière’s “Expériences de Phisique,” of which latter five
editions were printed respectively in 1709, 1718, 1728, 1734 and 1741.
REFERENCES.--“La Grande Encycl.,” Vol. VI. p. 897; Michaud,
“Biog. Univ.,” Vol. IV. p. 354; Dr. J. Thomas, “Univ. Pr.
Dict.,” 1886, p. 386.
=A.D. 1702.=--Marcel (Arnold), Commissioner of the Navy at Arles,
publishes a pamphlet dedicated to the King, and entitled “The Art of
Making Signals, both by Sea and by Land,” wherein he affirms that he
has “communicated frequently at the distance of two leagues (in as
short a space of time as a man could write down and form exactly the
letters contained in the advice he would communicate), an unexpected
piece of news that took up a page in writing.” The particulars of this
invention are, however, wanting.
Marcel reports many well-authenticated instances where, as already
mentioned by Mæstro Giulio Cæsare (A.D. 1590), iron bars have become
temporarily magnetic by position alone.
REFERENCES.--Snow Harris, “Rudim. Mag.,” I and II. pp. 91,
92; also “Emporium of Arts and Sciences,” 1812, Vol. I. p.
301; _Phil. Trans._, Vol. XXXVII. p. 294, also the following
abridgments: Baddam, Vol. IX, 1745, p. 278; Eames and Martyn,
Vol. VI. part. ii. p. 270; Hutton, Vol. VII. p. 540.
=A.D. 1702.=--Kæmpfer (Engelbrecht), German physician and naturalist
(1651–1716), describes in his “Amœnitates Exoticæ,” experiments made by
him upon the electric _torpedo_ (Leithead, 1837, Chap. XII). He insists
that any person may avoid all sensation of the shock by merely holding
the breath while touching the animal. This apparently improbable fact
has since been confirmed, however, by many scientists; the accurate
observations of Mr. Walsh (A.D. 1773) on the subject, reported in
the _Phil. Trans._ for 1773–1774–1775, claiming especial attention
(Larousse, “Dict.,” Vol. IX. p. 1144).
=A.D. 1704.=--Amontons (Guillaume), an ingenious mechanician and
scientist, exhibits before the royal family of France, and before the
members of the Académie des Sciences, his system of communicating
intelligence between distant points through the agency of magnifying
glasses--telescopes. The “Mémoires de l’Académie,” 1698–1705, contain
an account of his many scientific productions.
REFERENCES.--Larousse, “Dict.,” Vol. I. pp. 282–283; Appleton’s
“Cyclop.,” Vol. I. p. 432.
=A.D. 1705.=--Witson (Nicholaes), Burgomaster of Amsterdam, announces
at p. 56 of his “Noord en Oost Tartarye,” that the nautical compass was
in use by the Coreans in the second half of the seventeenth century.
=A.D. 1705.=--Hauksbee (Francis), English natural philosopher and
Curator of the Royal Society, makes, before the latter, several
experiments on the _mercurial phosphorus_. He shows that a considerable
quantity of light can be produced by agitating mercury in partly
exhausted as well as in thoroughly exhausted glass vessels. When the
mercury is made to break into a shower, flashes of light are seen to
start everywhere “in as strange a form as lightning.”
He also showed light _in vacuo_ produced by rubbing amber and by
rubbing glass upon woollen. He says (Priestley, “Hist. and Present
State of Electricity,” London, 1775, p. 19) that every fresh glass
first gave a purple and then a pale light, and that woollen, tinctured
with salt or spirits, produced a new, strong and fulgurating light.
Hauksbee constructed a powerful electrical machine wherein the Von
Guericke sulphur globe was replaced by one of glass, as had already
been done by Sir Isaac Newton (at A.D. 1675). With it he found
that upon exhausting the air, whirling the globe rapidly and placing
his hand upon the outside, a strong light appeared upon the interior,
and that the light would show itself also upon the outside when air was
let into the globe (“Physico-Mech. Exp.,” pp. 12, 14, 26, 32, 34).
The machine, which the celebrated mechanician Leupold had constructed
at Leipzig for Mr. Wolfius, only differed from the original one made
by Hauksbee in that the glass globe turned vertically instead of
horizontally.
Other experiments with coated glass globes, globes of sulphur, etc.,
are detailed in the “Physico-Mech. Exp.,” as indicated at pp. 21–24
the Priestley work above alluded to. At the last-named page he says:
“That Mr. Hauksbee, after all, had no clear idea of the distinction of
bodies into electrics and non-electrics appears from some of his last
experiments, in which he attempted to produce electrical appearances
from metals, and from the reasons he gives for his want of success in
those attempts.”
Hauksbee also gave some attention to the study of the laws of magnetic
force, and the results published in the _Phil. Trans._, Vol.
XXVII. for 1710–1712, p. 506, giving a law of force varying as the
sesqui-duplicate ratio of the distances, were subsequently confirmed
by Taylor and by Whiston in the _Phil. Trans._ for 1721 (Noad,
“Manual of Elec.,” 1859, p. 579).
REFERENCES.--Aglave et Boulard, “Lumière Electrique,” Paris,
1882, p. 18; Priestley, “Familiar Intr. to Study of Elec.,”
London, 1786, p. 60; _Phil. Trans._, Vol. XXV. pp. 2327, 2332;
Vol. XXVI, 1708–1709, pp. 82–92; Vol. XXIX, 1714–1716, p. 294
(with Brooke Taylor); also the following abridgments: Hutton,
Vol. V. pp. 270, 307, 324, 344, 355, 411–416, 452, 509, 528,
696; Jones, Vol. IV. p. 295; Baddam, 1745, Vol. V. pp. 33–37,
41–43, 112, 114–117, 483; Thos. Thomson, “Hist. of the Roy.
Soc.,” London, 1812, p. 430; _Chemical News_, Vol. II. p. 147;
Nicolas Desmarets, “Expériences,” etc., Paris, 1754, in “Recueil
des Mémoires de l’Acad. des Sciences.”
=A.D. 1705.=--Keill (John), M.A., F.R.S., Savilian Professor of
Astronomy, is the author of “Introductio ad Veram Physicam, etc.,”
of which other editions appeared in 1725, 1739 and 1741, and a good
English translation of which was published at Glasgow in 1776.
The last named is entitled “An Introduction to Natural Philosophy, or
Lectures in Physics read in the University of Oxford in the Year 1700.”
In Lecture VIII he states: “It is certain that the magnetic attractions
and directions arise from the structure of parts; for if a loadstone
be struck hard enough, so that the position of its internal parts be
changed, the loadstone will also be changed. And if a loadstone be put
into the fire, insomuch that the internal structure of the parts be
changed or wholly destroyed, then it will lose all its former virtue
and will scarce differ from other stones.... And what some generally
boast of, concerning effluvia, a subtile matter, particles adapted to
the pores of the loadstone, etc., does not in the least lead us to a
clear and distinct explication of these operations; but notwithstanding
all these things, the magnetick virtues must be still reckoned amongst
the occult qualities.”
=A.D. 1706.=--Hartsoeker (Nicolas), Dutch natural philosopher, friend
of Christian Huyghens, while Professor of Mathematics at Düsseldorf,
writes his “Conjectures Physiques,” four editions of which were
published during the three years 1708, 1710 and 1712.
The Tenth Discourse of the Second Book (pp. 140–182) treats of the
nature and properties of the loadstone and gives numerous observations
concerning magnetical phenomena, which are well illustrated. He says
that many ordinary stones have become magnetic after being long exposed
to the air, in consequence of iron penetrating them. He believes
that the native loadstone is made up of ordinary stone and of iron
containing many small bodies through which run magnetic channels;
that the latter are held together so strongly as to be disintegrated
with difficulty, and that they are filled with a subtile matter which
circulates incessantly through and around them.
The First Discourse of the Fourth Book treats of Meteors, and at pp.
91–99 of his “Eclaircissements, ...” published in 1710 he gives further
reports of his curious observations on magnetic phenomena.
REFERENCES.--“Journal des Sçavans,” Vol. XXIV for 1696, pp.
649–656.
For particulars of the very celebrated natural philosopher,
Christian Huyghens--Hugenius van Zuglichen (1629–1695) above
alluded to, consult: the “Vita Hugenii,” prefixed to his
“Opera Varia,” published by Van ’Sgravesande in 1724; “Meyer’s
Konversations-Lexikon,” Leipzig und Wien, 1895, Vol. IX. pp.
93–94, also the biography, embracing a detailed list of his
geometrical, mechanical, astronomical and optical works at pp.
536–538 of the “English Cyclopædia”; Vol. II. of Houzeau et
Lancaster, “Bibliog. Générale,” p. 169; “Le Journal des Savants”
for May 1834, April 1846, July 1888, April 1896, Feb. 1898, Oct.
1899; “Histoire des Sciences Math. et Phys.,” Maximilien Marie,
Paris, 1888, Vol. V. pp. 15–140; “Hist. et Mém. de l’Acad. Roy.
des Sc.,” Vol. I. p. 307; Hartsoeker’s biography at pp. 307–308
of the “Engl. Cycl.,” Vol. III, 1867.[49]
=A.D. 1707.=--J. G. S. (not, as many suppose, Jean George Sulzer)
publishes “Curious Speculations during Sleepless Nights” 8vo, Chemnitz,
wherein appears the first account of the development, by heat, of
electricity in the _tourmaline_, which latter, it is therein
stated, was first brought from Ceylon by the Dutch in 1703. Another
report of the above appears in the _Mémoires de l’Académie des
Sciences_ of Paris for 1717.
REFERENCE.--Beckmann, Bohn, 1846, Vol. I. pp. 86–98.
=A.D. 1708.=--Wall (Dr. William), a prominent English divine,
communicates to the Royal Society (_Phil. Trans._, Vol. XXVI. No.
314, p. 69) the result of his experiments, showing him to have been
the first to establish a resemblance of electricity to thunder and
lightning.
He found that, upon holding tightly in the hand a large bar of amber
and rubbing it briskly against woollen cloths, “a prodigious number of
little cracklings was heard, every one of which produced a small flash
of light (spark); and that when the amber was drawn lightly through
the cloth it produced a spark but no crackling.” He observed that
“by holding a finger at a little distance from the amber a crackling
is produced, with a great flash of light succeeding it, and, what is
very surprising, on its eruption it strikes the finger very sensibly,
wheresoever applied, with a push or puff like wind. The crackling is
fully as loud as that of charcoal on fire.... This light and crackling
seem in some degree to represent thunder and lightning.”
REFERENCES.--Bakewell, “Electric Science,” p. 13; Aglave et
Boulard, “Lumière Electrique,” 1882, p. 17; Thos. Thomson, “An
Outline of the Sciences of Heat and Electricity,” London, 1830,
pp. 314, 463; Thos. Thomson, “Hist. of the Roy. Soc.,” London,
1812, p. 431; see also the following abridgments of the _Phil.
Trans._; Hutton, Vol. V. p. 408 and Baddam of 1745, Vol. V. p.
111.
=A.D. 1712.=--The great Japanese Encyclopædia, _Wa-Kan-san siü
tson-ye_, describes the compass, _zi-siak-no-fari_, at Vol. XV. folio
3, _recto_ (Klaproth, “Lettre à M. de Humboldt,” etc., 1834, p. 107).
=A.D. 1717.=--Leméry (Louis), two years after the death of
his distinguished father, Nicolas Leméry, exhibits a stone (the
_tourmaline_) brought from Ceylon, and announces, to the French
Académie des Sciences, that it possesses the electrical property of
attracting and repelling light bodies after being warmed.
Carl Linnæus (1707–1777) alludes to the experiments of Leméry, in
his _Flora Zeylanica_, and mentions the stone under the name of
_lapis electricus_. (See, for Carl Linnæus, “Thesaurus Litteraturæ
Botanicæ,” G. A. Pritzel, Lipsiæ, 1851, pp. 162–169, also “Guide to
the Literature of Botany,” by Benj. Daydon Jackson, London, 1881, pp.
xxxvi, etc.)
The first scientific examination of the electric properties of the
tourmaline was, however, made by Æpinus in 1756, and published in
the Memoirs of the Berlin Academy. Æpinus showed that a temperature
of between 99½° and 212° F. was necessary for the development of its
attractive powers.
Of the electricity of crystals, Gmelin, in his “Chemistry” (Vol. I. p.
319), names the following discoverers: Æpinus (tourmaline)--see A.D.
1759; Canton (topaz)--see A.D. 1753; Brard (axinite)--see A.D. 1787;
Haüy (boracite, prehnite, sphene, etc.)--see A.D. 1787; Sir David
Brewster (diamond, garnet, amethyst, etc.)--see A.D. 1820; and Wilhelm
Gottlieb Hankel (borate of magnesia, tartrate of potash, etc.).
REFERENCES.--Becquerel, “Résumé,” 1858, p. 11; Leithead,
“Electricity,” p. 239; “Ph. Hist. and Mem. of Roy. Ac. of Sc.
at Paris,” London, 1742, Vol. V. p. 216; “Journal des Sçavans,”
Vol. LXX for 1721, pp. 572–573 on the tourmaline.
=A.D. 1720.=--Grey--Gray (Stephen), a pensioner of the Charter House
and Fellow of the Royal Society, makes known through his first paper in
the _Phil. Trans._ the details of the important line of investigation
which finally led to the discovery of the principle of electric
conduction and insulation as well as to the fact, not the principle, of
induction (see Æpinus, A.D. 1759). _Thus, to Grey is due the credit of
having laid the foundation of electricity as a science._
He proved that electricity can be excited by the friction of feathers,
hair, linen, paper, silk, etc., all of which attract light bodies
even at a distance of eight or ten inches. He next discovered that
electricity can be communicated from excited bodies to bodies
incapable of ready excitation. When first suspending a hempen line with
pack threads he could not transmit electricity, but when suspending
the line with silken threads he transmitted the electrical influence
several hundred feet. The latter he did at the suggestion of his friend
Granville Wheeler--Wheler--(not Checler, as Aglave et Boulard have it
in “Lumière Electrique,” p. 20), thinking that “silk might do better
than pack thread on account of its smallness, as less of the virtue
would probably pass off by it than by the thickness of the hempen line
which had been previously used.” They both tried experiments with
longer lines of pack thread, but failed, as they likewise did after
substituting thin brass wire for the thread. This afterwards led to the
discovery of other insulating substances, like hair, resin, etc. During
the months of June 1729, and August 1730, Grey and Wheeler succeeded in
transmitting electricity through pack thread supported by silken cords
a distance of 765 feet, and through wire at a distance of 800–886 feet.
Grey demonstrated also that electric attraction is not proportioned to
the quantity of matter in bodies, but to the extent of their surface,
and he likewise discovered the conducting powers of fluids and of
the human body. Of the cracklings and flashes of light he remarks:
“And although these effects are at present but _in minimis_,
it is probable, in time, there may be found out a way to collect a
greater quantity of the electric fire, and consequently to increase
the force of that power, which by several of those experiments, if we
are permitted to compare great things with small, seems to be of the
same nature with that of thunder and lightning” (_Phil. Trans._,
abridgment of John Martyn, Vol. VIII. p. 401).
Stephen Grey may be said to have continued his experiments while lying
upon his death-bed, for, unable to write, he dictated to the last, as
best he could, the progress he had made in his studies to Dr. Mortimer,
the Secretary of the Royal Society (_Phil. Trans._, 1735–1736,
Vol. XXXIX. p. 400).
Grey’s own description of a new electric planetarium deserves
reproduction here: “I have lately made several new experiments upon
the projectile and pendulous motions of small bodies by electricity;
by which small bodies may be made to move about larger ones, either
in circles or ellipses, and those either concentric or excentric to
the centre of the large body about which they move, so as to make many
revolutions about them. And this motion will constantly be the same way
that the planets move around the sun, viz. from the right hand to the
left, or from west to east. But these little planets, if I may so call
them, move much faster in their apogeon than in the perigeon part of
their orbits, which is directly contrary to the motion of the planets
around the sun.” To this should be added the following description of
the manner in which these experiments can be made: “Place a small iron
globe, of an inch or an inch and a half in diameter, on the middle of
a circular cake of rosin, seven or eight inches in diameter, greatly
excited; and then a light body, suspended by a very fine thread, five
or six inches long, held in the hand over the centre of the cake,
will, of itself, begin to move in a circle around the iron globe, and
constantly from west to east. If the globe is placed at any distance
from the centre of the circular cake, it will describe an ellipse,
which will have the same excentricity as the distance of the globe
from the centre of the cake. If the cake of rosin be of an elliptical
form, and the iron globe be placed in the centre of it, the light body
will describe an elliptical orbit of the same excentricity with the
form of the cake. If the globe be placed in or near one of the foci
of the elliptical cake, the light body will move much swifter in the
apogee than in the perigee of its orbit. If the iron globe is fixed on
a pedestal an inch from the table, and a glass hoop, or a portion of
a hollow glass cylinder, excited, be placed around it, the light body
will move as in the circumstance above mentioned, and with the same
varieties.”
REFERENCES.--Priestley, “Hist. and Present State of Elec.,”
1775, pp. 26–42, 55–63; and “A New Universal History of Arts and
Sciences,” _Electricity_, Vol. I. p. 460; _Saturday Review_,
August 21, 1858, p. 190; Wilson, “Treatise,” 1752, Section IV.
prop. i. p. 23, note; _Phil. Trans._, Vol. XXXI. p. 104; Vol.
XXXVII. pp. 18, 227, 285, 397; Vol. XXXIX. pp. 16, 166, 220,
also the following abridgments: Hutton, Vol. VI. p. 490; Vol.
VII. pp. 449, 536, 566; Vol. VIII. pp. 2, 51, 65, 316; Reid
and Gray, London, 1733, Vol. VI. pp. 4–17 (Granville Wheler);
Eames and Martyn, Vol. VI. part ii. pp. 7, 9, 15, and Part IV.
p. 96; Vol. VII. pp. 18–20, 231; John Martyn, Vol. VIII. part
ii. pp. 397, 403, 404 (Dr. C. Mortimer); Baddam, Vol. IX, 1745,
pp. 145–160, 244, 272, 340, 497; “An Outline of the Sciences of
Heat and Electricity,” Thomas Thomson, London, 1830, p. 344;
and Thos. Thomson’s “Hist. of the Roy. Soc.,” London, 1812, p.
431; Weld, “Hist. of Roy. Soc.,” Vol. I. p. 466; “A course of
lectures on Nat. Philos. and the Mechanical Arts,” by Thos.
Young, London, 1807, Vol. II. p. 417; “Hist. de l’Académie des
Sciences,” 1733, p. 31; “Jour. Litter.” de 1732, à la Haye, pp.
183, 186, 187, 197; “Hist. de l’Académie Royale de Berlin,”
1746, p. 11; “Journal des Sçavans,” Vol. CXXV for 1741, pp.
134–141, and Vol. CXXVI for 1742, pp. 252–263. For Granville
Wheeler, consult _Phil. Trans._, Vol. XLI. pp. 98, 118, also
the following abridgments: Hutton, Vol. VIII. pp. 306–320;
John Martyn, Vol. VIII. part ii. pp. 406, 412, 415. For Dr. C.
Mortimer, consult _Phil. Trans._, Vol. XLI. p. 112 and John
Martyn’s abridgments, Vol. VIII. part ii. pp. 404–412.
=A.D. 1721.=--Taylor (Brooke), LL.D., F.R.S. (1685–1731), an eminent
English mathematician, past Secretary of the Royal Society, and one of
the ablest geometers of his time--“the only one who, after the retreat
of Newton, could safely enter the lists with the Bernoullis”--publishes
his “Experiments on Magnetism” in _Phil. Trans._, No. 368.
In order to arrive at a proper determination of the laws of magnetic
force, Dr. Taylor--and also Whiston and Hauksbee--according to Sir
David Brewster, considered “the deviation of a compass needle from the
meridian, produced by the action of a magnet at different distances;
and the conclusion which they all drew from their experiments was that
the magnetic force was proportional to the sines of half the arcs of
deviation, or nearly in the inverse sesqui-duplicate ratio of the
distance, or as the square roots of the fifth powers of the distances.
Dr. Taylor had already come to the conclusion that the force was
different in various magnets, and decreased quicker at great distances
than at small ones, an experimental fact, as shown by Sir W. S. Harris,
‘Rud. Mag.,’ Part III. p. 224.”
In Dr. Thomas Thomson’s “History of the Royal Society” we read, however
(p. 461), that Brooke Taylor, and after him Musschenbroek, attempted
without success to determine by experiment the rate at which the
magnetic attractions and repulsions vary. This rate was successfully
investigated by the subsequent experiments of Lambert, Robison and
Coulomb. The nature of magnetic curves was first satisfactorily
explained by Lambert, Robison and Playfair. Brooke Taylor gave four
poles to a wire by touching it at one end or at various parts, as
indicated in _Phil. Trans._, Vol. XXIX. p. 294, and Vol. XXXI. p.
204.
REFERENCES.--Whewell, “Hist. of the Ind. Sciences,” 1859, Vol.
I. pp. 359, 375; Vol. II. p. 31; “General Biog. Dict.,” London,
1816, Vol. XXIX. pp. 163–166; _Phil. Trans._ for 1714–1716, Vol.
XXIX. p. 294 and the following abridgments: Hutton, Vol. VI. p.
528; Reid and Gray, Vol. VI. pp. 17, 159; Hy. Jones, Vol. IV.
part ii. p. 297; Eames and Martyn, Vol. VI. part ii. p. 253.
=A.D. 1722.=--Graham (George), a celebrated optician and instrument
maker in London, is the first to distinctly make known the _diurnal
and horary variations_ of the magnetic needle, traces of which had
been merely recognized as facts by Gellibrand, in 1634, and by the
Missionary Father Guy-Tachard at Louvo, in Siam, during 1682. He finds
that its northern extremity begins to move westward at about seven
or eight o’clock in the morning, and continues to deviate in that
direction until about two o’clock in the afternoon, when it becomes
stationary; it soon begins to return to the eastward and becomes
again stationary during the night. Graham made nearly a thousand
observations, between the 6th of February and the 12th of May, 1722,
and found that the greatest westerly variation was 14° 45’, and the
least 13° 50’; in general, however, it varied between 14° and 14° 35’,
giving 35’ for the amount of the daily variation.
Graham’s discovery--afterwards amplified by Anders Celsius
(A.D. 1740)--attracted but little attention until 1750, when
the subject was ably taken up by Wargentin, Secretary to the Swedish
Academy of Sciences. Between 1750 and 1759 Mr. John Canton made about
4000 observations on the same subject, and was followed by the Dutch
scientist Gerard van Swieten, the favourite pupil of Boerhaave, with
like results.
As Dr. Lardner states (“Lectures on Science and Art,” 1859, Vol. II.
p. 115), the same phenomenon has been observed more recently by Col.
Beaufoy (at A.D. 1813), by Prof. Hansteen (at A.D. 1819) and by many
others. He further states that Cassini, who observed the _diurnal_
variation of the needle at Paris, found that neither the solar heat nor
light influenced it, for it was the same in the deep caves constructed
under the Observatory in Paris, where a sensibly constant temperature
is preserved, and from which light is excluded, as at the surface. In
northern regions these diurnal changes are greater and more irregular;
while, toward the line, their amplitudes are gradually diminished until
at length they disappear altogether.
It was Graham who first entertained the idea of measuring the magnetic
intensity through the vibrations of the needle, a method subsequently
used by Coulomb, and which many believe was invented by the latter.
From the observations made by Humboldt and by Gay-Lussac in this
manner, Biot has reduced the variation of intensity in different
latitudes.
REFERENCES.--“_Am. Journal Science_,” Vol. XXX. p. 225; Walker,
“Magnetism,” Chap. II; Fifth Dissertation of the Eighth
“Britannica,” Vol. I. p. 744; also _Phil. Trans._ 1724–1725,
Vol. XXXIII. p. 332, and pp. 96–107 (“An Account of Observations
Made of the Horizontal Needle at London, 1722–1723, by Mr.
George Graham”) and the following abridgments: Reid and Gray,
Vol. VI. pp. 170, 187; Hutton, Vol. VII. pp. 27, 94; Vol. IX.
p. 495; Eames and Martyn, Vol. VI. part ii. pp. 28, 280, 290;
Baddam, 1745, Vol. VIII. p. 20; John Martyn, Vol. X. part ii. p.
698; _An de chimie_ for 1749, Vol. XXV. p. 310.
=A.D. 1725.=--Horrebow--Horreboe--(Peter), was a Danish physicist
(1679–1764), who studied medicine for a time and then became a pupil
of the celebrated mathematician and astronomer Olaus Rœmer (1644–1710,
best known by his discovery of the finite velocity of light), whom he
succeeded in the University of Copenhagen.
His earliest work, “Clavis Astronomiæ,” first appeared during 1725, but
it is only in the second and enlarged new edition of it in Horrebow’s
“Operum Mathematico-Physicorum,” Havn. 1740, Vol. I. p. 317, that
will be found the passage (s. 226) in which the luminous process of
the sun is characterized as a perpetual northern light. Humboldt,
who mentions the fact (“Cosmos,” 1859, Vol. V. p. 81) suggests that a
comparison be made of Horrebow’s statement with the precisely similar
views held by Sir William Herschel (1738–1822) and Sir John Frederick
William Herschel (1792–1871). He says that Horrebow, who did not
confound gravitation with magnetism, was the first who thus designated
the process of light produced in the solar atmosphere by the agency of
powerful magnetic forces (“Mémoires de Mathématiques et de Physique,
présentés à l’Académie Royale des Sciences,” Vol. IX. 1780, p. 262;
Hanow, in Joh. Dan. Titius’s “Gemeinützige Abhand. über natür. Dinge,”
1768, p. 102), and, with reference to the Herschels he thus expresses
himself: “If electricity, moving in currents, develops magnetic forces,
and if, in accordance with an early hypothesis of Sir Wm. Herschel
(_Phil. Trans._ for 1795, Vol. LXXXV. p. 318; John Herschel,
“Outlines of Astronomy,” p. 238; also, Humboldt, “Cosmos,” Vol. I. p.
189), the sun itself is in the condition of a perpetual northern light
(I should rather say of an electro-magnetic storm) we should seem
warranted in concluding that solar light transmitted in the regions of
space by vibrations of ether, may be accompanied by electro-magnetic
currents” (“Dict. of Nat. Biog.,” for John and William Herschel, Vol.
XXVI. pp. 263–274).
REFERENCES.--Larousse, “Dict. Univ.,” Vol. IX. p. 397; Wolf,
“Hist. Ordbog.,” Vol. VII. pp. 194–199; Nyerup, “Univ. Annalen”;
Houzeau et Lancaster, “Bibliographie,” 1882, Vol. II. p. 166.
Three of the children of Peter Horrebow, almost equally distinguished
for their learning, are: Nicolas Horrebow (1712–1760), who made
physical and astronomical observations in Iceland and published an
able report thereon during 1752; Christian Horrebow (1718–1776), who
succeeded his father in 1753 as astronomer in the Copenhagen University
and who wrote several important scientific treatises; and Peter
Horrebow (1728–1812), who was professor of mathematics and philosophy,
and published works on geometry, meteorology and astronomy.
Much of interest concerning the above will also be found in the
“Abstracts of Papers ... Roy Soc.,” Vol. II. pp. 208, 249, 251, and in
the “Catalogue of Sc. Papers ... Roy. Soc.,” Vol. III. pp. 322–328;
Vol. VI. p. 687; Vol. VII. p. 965.
=A.D. 1726.=--Wood (John), an English architect of considerable
repute, is said to have shown that the electric fluid could be conveyed
through wires a long distance, and, during the year 1747, one of the
earliest applications of Wood’s discovery was made by Dr. William
Watson (see A.D. 1745), who extended his experiments over a
space of four miles, comprising a circuit of two miles of wire and an
equal distance of ground.
REFERENCES.--Alexander Jones, “Sketch of the Elect. Teleg.,” New
York, 1852, p. 7; Charles F. Briggs, “Story of the Telegraph,”
1858, p. 18.
=A.D. 1729.=--Hamilton (James), who became sixth Earl of
Abercorn--also called Lord Paisley--publishes “Calculations and Tables
relating to the attractive virtue of loadstones ...” containing very
valuable data and wherein he is the first to give the true law of the
lifting capacity of magnets, as follows: “The principle upon which
these tables are formed is this: That if two loadstones are perfectly
homogeneous, that is if their Matter be of the same specifick parity,
and of the same virtue in all parts of one stone, as in the other; and
that like parts of their surfaces are cap’d or arm’d with iron; then
the weights they sustain will be as the squares of the cube roots of
the weights of the loadstones; that is, as their surfaces.”
Gilbert treats of armed loadstones, Book II. chaps. xvii-xxii. In
connection with the increased energy which magnets acquire by being
armed, that is, fitted with a cap of polished iron at each pole, Dr.
Whewell remarks that it is only at a later period any notice was taken
“of the distinction which exists between the magnetical properties of
soft iron and of hard steel; the latter being susceptible of being
formed into _artificial magnets_, with permanent poles; while soft
iron is only _passively magnetic_, receiving a temporary polarity
from the action of a magnet near it, but losing this property when the
magnet is removed. About the middle of the last century various methods
were devised of making artificial magnets, which exceeded in power all
magnetic bodies previously known” (“Hist. of the Ind. Sc.,” 1859, Vol.
II. p. 220).
Hamilton alludes to a loadstone weighing 139 grains, with a lifting
power of 23,760 grains! We have referred, amongst others, to the
loadstone belonging to Sir Isaac Newton at A.D. 1675, and to
the wonderful collection belonging to Mr. Butterfield at A.D.
1809. A loadstone weighing twelve ounces, capable of lifting sixty
pounds of iron, is referred to in Terzagus, “Musæum Septalianum,” 1664,
p. 42, while another weighing two and a half grains and lifting 783
grains is mentioned at p. 272, Vol. III. of the “Records of General
Science”; and Salviatus (“Dialogues of Galileo,” Dial. III) alludes
to one in the Academy of Florence which, unarmed, weighed six ounces
and could lift but two ounces, but when armed had a lifting power
of 160 ounces. At pp. 317–318, Part III of Nehemiah Grew’s “Musæum
Regalis Societatis,” London, 1681--also 1686--allusion is made to a
loadstone found in Devonshire, weighing about sixty pounds, which moved
a needle nine feet distant. Grew then refers to Athan. Kircher and to
Vincent Leotaud as having published what is said of the loadstone by
Gilbert and others, and he likewise states: “Those that travail through
the vast deserts of Arabia, have also a needle and a compass whereby
they direct themselves in their way, as Mariners at sea [Majoli,
‘Colloquia’]; the power of the magnet dependeth not upon its bulk--the
smaller being usually the stronger....”
REFERENCES.--_Phil. Trans._ for, 1729–1730, No. 412, Vol. XXXVI.
p. 245, and for July 1888, also Hutton’s abridgments, Vol. VII.
p. 383; V. T. M. Van der Willigen, “Arch. du Musée Teyler,”
1878, Vol. IV; Jacobi Rohaulti, “Physica,” 1718, Part III. cap.
8, p. 403, or the English translation by Dr. Clarke, 1728,
Vol. II. p. 181; P. W. Hacker, “Zur theorie des magnetismus,”
Nürnberg, 1856; Ath. Kircher, “Magnes. ...” 1643, lib. i. part
ii. p. 63; Daniel Bernoulli, “Acta Helvetica,” 1758, Vol. III.
p. 223; Nic. Cabæus “Philosophia Magnetica,” 1629, lib. iv. cap.
42, p. 407; Kenelme Digby, “The Nature of Bodies,” 1645, Chap.
XXII. p. 243; “Dict. of Nat. Biog.” Vol. XXIV. p. 185.
=A.D. 1729–1730.=--Savery (Servington), English mechanician, succeeds
in imparting magnetism to hard steel bars three-fourths of an inch
square and sixteen inches long, by fitting one bar with an armature at
each end and touching other bars with it whilst held in the magnetic
meridian in the line of the inclined needle.
It was shown by Savery that his artificial magnets were preferable
to loadstones. The first recorded attempt to make artificial magnets
is credited to one John Sellers, believed to be the author of “The
Practical Navigator,” of which the earliest edition appeared in 1669,
and of “The Coasting Pilot,” published about 1680. An “Answer to Some
Magnetical Inquiries Proposed in (the preceding) No. 23, pp. 423–424,”
will be found in _Phil. Trans._ for 1667, Vol. II. pp. 478–479
and in the following abridgments: Baddam, 1745, Vol. I. p. 86; Hutton,
Vol. I. p. 166 (as of No. 26, p. 478); John Lowthorp, Vol. II. p. 601.
Reference is likewise made to this invention of Sellers at Vol. I. p.
86 of the “Memoirs of the Royal Society,” London, 1739, and in a paper
by Réaumur, in the “Mémoires de l’Académie Française” for the year 1723.
REFERENCES.--Savery, “Magnetical Observations and Experiments,”
also _Phil. Trans._, Vol. XXXVI. pp. 295–340; and the following
abridgments: Hutton, Vol. VII. p. 400; Reid and Gray, Vol. VI.
p. 166; Eames and Martyn, Vol. VI. p. 260; Baddam, 1745, Vol.
IX. p. 57; Geo. Adams, “Essay on Electricity,” 1785, p. 451.
=A.D. 1731.=--On the 25th of November the Royal Society were
honoured by a visit from the Prince of Wales and the Duke of Lorraine,
the last named being enrolled as a member during the evening.
Experiments were performed “On the strength of Lord Paisley’s
loadstone,” “On Dr. Frobenius’s phlogiston,” and “On the electrical
observations of Mr. Stephen Grey.” These experiments which, it is
said, “succeeded notwithstanding the largeness of the company,” showed
the facility with which electricity passes through great lengths of
conductors and are worth noting as being the first of their nature.
=A.D. 1732.=--Régnault (Le Père Noël) gives in “Les Entretiens
Physiques,” etc., Vol. I. Nos. 15 and 16, the tables of the declination
at Paris from the years 1600–1730, and treats at length of the merits
of the loadstone and of the magnetic needle.
In Vols. II, IV and V he discourses about the extent of the magnetic
fluid and explains the phenomena of meteors, St. Elmo’s fire, thunder,
etc., besides recording the experiments of Grey, Dufay and others.
=A.D. 1733.=--Dufay (Charles François de Cisternay), French scientist
and superintendent of the _Jardin du Roi_, now the _Jardin des
Plantes_, of Paris (in which latter position he was succeeded by
Buffon), communicates to the French Academy of Sciences the history of
electricity brought down to the year 1732 (_Dantzig Memoirs_, Vol. I.
p. 195).
He is said to have originated the theory of two kinds of electricity
permeating matter and producing all the known phenomena of attraction,
repulsion and induction, though the honour of this important discovery
should be shared by M. White, who was associated at one time with
Stephen Grey and who, it appears, independently discovered the fact
while in England. Dufay thus announces his discovery: “... there are
two kinds of electricity, very different from one another, one of
which I call _vitreous_ (positive) and the other _resinous_ (negative)
electricity. The first is that of glass, rock crystal, precious stones,
hairs of animals, wool and many other bodies. The second is that of
amber, copal, gum-lac, silk, thread, paper and a vast number of other
substances. The characteristics of these two electricities are that
they repel themselves and attract each other. Thus a body of the
vitreous electricity repels all other bodies possessed of the vitreous,
and, on the contrary, attracts all those of the resinous electricity.
The resinous also repels the resinous and attracts the vitreous. From
this principle one may easily deduce the explanation of a great number
of the phenomena; and it is probable that this truth will lead us to
the discovery of many other things” (see Franklin, at A.D. 1752, and
Symmer, at A.D. 1759).
Upon repeating Grey’s experiments, Dufay observed, amongst other
things, that, by wetting pack thread, electricity was more readily
transmitted through it, and he was enabled thus easily to convey the
fluid a distance of 1256 feet, though the wind was high and although
the line made eight returns.
REFERENCES.--Fontenelle, “Eloge”; Priestley, “History and
Present State of Electricity,” 1775, Period IV. pp. 43–54;
Sturgeon, _Lectures_, 1842, p. 23; “An Epitome of El. and Mag.,”
Philad., 1809, p. 29; _Mém. de l’Acad. Royale des Sciences_
for 1733, pp. 23, 28, 76, 83, 233–236, 251, 252, 457; also for
the years 1734, pp. 303, 341, and 1737, pp. 86, 307; _Phil.
Trans._, Vol. XXXVIII. p. 258; also the following abridgments:
Hutton, Vol. VII. p. 638; John Martyn, Vol. VIII. part ii. p.
393; Baddam, Vol. IX. p. 497; Thos. Thomson, “An Outline of the
Sciences of Heat and Electricity,” London, 1830, p. 344 and
Thos. Thomson, “Hist. of the Roy. Soc.,” London, 1812, p. 432;
“Electricity in the Service of Man,” R. Wormell (from the German
of Dr. Urbanitzky), London, 1900, p. 14; “Journal des Sçavans,”
Vol. XCIII for 1731, pp. 383–388; Vol. C for 1733, p. 244; Vol.
CIV for 1734, p. 479; Vol. CXII for 1737, p. 65; Vol. CXV for
1738, p. 173; Vol. CXXIX for 1743, p. 501.
=A.D. 1733.=--Winckler (Johann Heinrich), a philosopher of Wingendorf,
Saxony, and Professor of Languages in the University of Leipzig, first
uses a fixed cushion in the electric machine for applying friction
instead of by means of the hand, and is, by many, believed to have been
the first to suggest the use of conductors as a means of protection
against lightning (see B.C. 600).
In March 1745, Winckler read a paper before the Royal Society, in which
he describes machines for rubbing tubes and globes, also a contrivance
with which he can give his globes as many as 680 turns in a minute.
Priestley states that the German electricians generally used several
globes at a time and that they could excite such a prodigious power
of electricity from “globes, whirled by a large wheel and rubbed with
woollen cloth or a dry hand, that, if we may credit their own accounts,
the blood could be drawn from the finger by an electric spark; the skin
would burst and a wound appear, as if made by a caustic.”
During the year 1746 Winckler made use of common electricity for
telegraphic communications by the discharge of Leyden jars through very
long circuits, in some of which the River Pleisse formed a part, and it
may be added that Joseph Franz had previously discharged the contents
of a jar through 1500 feet of iron wire while in the city of Vienna.
REFERENCES.--_Phil. Trans._, Vol. XLIII. p. 307; Vol. XLIV. pp.
211, 397; Vol. XLV. p. 262; Vol. XLVII. p. 231; Vol. XLVIII.
p. 772; also following abridgments: Hutton, Vol. IX. pp. 74,
109, 251, 345, 494; Vol. X. pp. 197, 529; John Martyn, Vol.
X. part ii. pp. 269, 273, 327, 345, 399; Priestley, 1775, on
the discoveries of the Germans, pp. 70–77; “Thoughts on the
Properties,” etc., Leipzig, 1744, pp. 146, 149.
=A.D. 1733.=--Brandt (Georg), Swedish chemist, gives in the “Memoirs
of the Academy” of Upsal an account of the experiments made by him to
show the possibility of imparting magnetism to substances which are not
ferruginous. He proved it in the case of the metal cobalt, and during
the year 1750 the able discoverer of nickel, Axel. F. de Cronstedt,
showed that the latter is likewise susceptible of this property.
REFERENCES.--Thomas, “Dict. of Biog.,” 1871, Vol. I. p. 428;
English Cyclopædia (Biography Supplement), 1872, p. 423.
=A.D. 1734.=--Polinière (Pierre), French physician and experimental
philosopher (1671–1734), member of the Society of Arts, entirely
revises the fourth edition of his “Expériences de Phisique” originally
issued in 1709. While the second volume contains but a short chapter
relative to electricity, meteoric disturbances, etc., the remainder
of the work gives very curious and interesting experiments with the
loadstone, making allusion to the observations of John Keill, besides
treating of the declination of the needle, etc.
REFERENCES.--“New Gen. Biog. Dict.,” London, 1850, Vol. XI. p.
177; Moréri, “Grand Dict. Hist.”; “Biog. Univ.” (Michaud), Vol.
XXXIII. p. 637; “Nouv. Biog. Gén.” (Hœfer), Vol. XL. p. 614;
Chaudon, “Dict. Hist. Univ.”
=A.D. 1734.=--Swedenborg (Emanuel), founder of the Church of New
Jerusalem, details in his “Principia Rerum Naturalium,” etc., the
result of experiments and sets forth the laws relating to magnetic
and electric forces and effects. The first explicit treatise upon the
close relationship existing between magnetism and electricity was,
however, written fourteen years later by M. Laurent Béraud (1703–1777),
Professor of Mathematics at the College of Lyons. Both Swedenborg and
Béraud recognized the fact that it is, as Fahie expresses it, the same
force, only differently disposed which produces both electric and
magnetic phenomena.
In “Results of an Investigation into the MSS. of Swedenborg,”
Edinburgh, 1869, p. 7, No. 16, Dr. R. L. Tafel makes following entry:
“A treatise on the magnet, 265 pages text and 34 pages tables, quarto.
This work is a digest of all that had been written up to Swedenborg’s
time on the subject, with some of his own experiments. According to the
title page, Swedenborg had intended it for publication in London during
the year 1722.”
The “Principia Rerum Naturalium” is the first volume of Swedenborg’s
earliest great work, “Opera Philosophica et Mineralia,” originally
published in Leipzig and Dresden 1734, which has justly been pronounced
a very remarkable cosmogony. In the “Principia” Part I. chap. ix.,
is to be found his treatment of what he calls the second or magnetic
element of the world; in Part III. chap. i. he gives a comparison of
the sidereal heaven with the magnetic sphere, but he devotes the whole
of Part II to the magnet in following chapters:
I. On the causes and mechanism of the magnetic forces;
II. On the attractive forces of two or more magnets, and the
ratio of the forces to the distances;
III. On the attractive forces of two magnets when their poles
are alternated;
IV. On the attractive forces of two magnets when their axes
are parallel or when the equinoctial of the one lies upon the
equinoctial of the other;
V. On the disjunctive and repulsive forces of two or more
magnets when the cognomical or inimical poles are applied to
each other;
VI. On the attractive forces of the magnet and of iron;
VII. On the influence of the magnet upon ignited iron;
VIII. On the quantity of exhalations from the magnet and their
penetration through hard bodies, etc.;
IX. On the various modes of destroying the power of the magnet;
and on the chemical experiments made with it;
X. On the friction of the magnet against iron, and on the force
communicated from the former to the latter;
XI. On the conjunctive force of the magnet, as exercised upon
several pieces of iron;
XII. On the operation of iron and of the magnet upon the
mariner’s needle; and on the reciprocal operation of one needle
upon another;
XIII. On other methods of making iron magnetical;
XIV. The declination of the magnet calculated upon the foregoing
principles;
XV. On the causes of the magnetic declination;
XVI. Calculation of the declination of the magnet for the year
1722, at London.
REFERENCES.--Béraud, “Dissertation,” etc., Bordeaux, 1748;
also Priestley, 1775, p. 191; “Biographie Universelle,” Vol.
III. p. 687; “Biog. Génér.,” Vol. XLIV. pp. 690–703; Daillant
de la Touche, “Abrégé des ouvrages de Swedenborg,” 1788;
J. Clowes, “Letters on the writings of Swedenborg,” 1799;
“Svenskt Biografiskt Handlexikon,” Herm. Hofberg, Stockholm,
pp. 368–369; “Swedenborg and the Nebular Hypothesis,” Magnus
Nyrén, astronomer at Observatory of Pulkowa, Russia, translated
from the “Viertel jahrschrift der Astronomischen Gesellschaft,”
Leipzig, 1879, p. 81, by Rev. Frank Sewall.
=A.D. 1735–1746.=--Ulloa (Don Antonio de), Spanish mathematician,
who left Cadiz May 26, 1735, for South America, whither he was sent
with Condamine and other French Academicians, as well as with Spanish
scientists, to measure a degree of the meridian, returned to Madrid
July 25, 1746, and shortly after gave an account of his experiences
during an absence of eleven years and two months.
In his “Voyage Historique de l’Amérique Méridionale,” Amsterdam and
Leipzig, 1752, he speaks (Vol. I. pp. 14–18 and Vol. II. pp. 30–31,
92–94, 113, 123, 128) of the defective magnetic needles given him
as well as of the means of correcting them, and he details at great
length the variations of the needle observed during the voyage. He also
alludes to the variation charts of Dr. Halley and to the alterations
therein made by advice of William Mountaine and Jacob Dooson--James
Dodson--of London, as well as to the methods of ascertaining the
variation of the magnetic needle pointed out both by Manuel de
Figueyredo, at Chaps. IX-X of his “Hidrographie ou Examen des Pilotes,”
printed at Lisbon in 1608, and by Don Lazare de Flores at Chap. I, part
ii. of his “Art de Naviguer,” printed in 1672. The latter, he says,
asserts, in Chap. IX, that the Portuguese find his method so reliable
that they embody it in all the instructions given for the navigation of
their vessels.
At pp. 66, 67, Chap. X of vol. ii. Ulloa makes the earliest recorded
reference to the _aurora australis_, as follows: “At half-past
ten in the evening, and as we stood about two leagues from the island
of _Tierra de Juan Fernandez_, we observed upon the summit of a
neighbouring mountain a very brilliant and extraordinary light....
I saw it very distinctly from its inception, and I noticed that it
was very small at first, and gradually extended until it looked like
a large, lighted torch. This lasted three or four minutes, when the
light began to diminish as gradually as it had grown, and finally
disappeared.”
Incidentally, it may be stated here that the very learned Dr. John
Dalton reported having seen the _aurora australis_ in England, and to
have besides observed the _aurora borealis_ as far as 45° latitude
south (see accounts in _Philosophical Transactions_, _Philosophical
Magazine_, _Manchester Transactions_ and _Nicholson’s Journal_), while
Humboldt remarks (“Cosmos,” 1849, Vol. I. p. 192, note) that in south
polar bands, composed of very delicate clouds, observed by Arago,
at Paris, on the 23rd of June, 1844, dark rays shot upward from an
arch running east and west, and that he had already made mention of
black rays resembling dark smoke, as occurring in brilliant nocturnal
northern lights.
References to the _aurora australis_ are made by the naturalist John
Reinhold Forster, in the article on “Aurora Borealis” of the “Encycl.
Britannica.”
For Mountaine and Dodson, consult the _Phil. Trans._, Vol. XLVIII.
p. 875; Vol. L. p. 329, also Hutton’s abridgments, Vol. XI. p. 149.
=A.D. 1738.=--Boze--Böse--(Georg Matthias) (1710–1761), Professor
of Philosophy at Wittemburg, publishes his “Oratio inauguralis de
electricitate,” which is followed, in 1746, by “Recherches sur la cause
et sur la véritable théorie de l’électricité,” and, in 1747, by his
completed “Tentamina electrica.”
To him is due the introduction in the electrical machine of the prime
conductor, in the form of an iron tube or cylinder. The latter was at
first supported by a man insulated upon cakes of resin and afterward
suspended by silken strings. M. Boze discovered that capillary tubes
discharging water by drops give a continuous run when electrified. He
also conveyed electricity by a jet of water from one man to another,
standing upon cakes of resin, at a distance of six paces, and likewise
employed the jet for igniting alcohol as well as other liquids.
REFERENCES.--Alglave et Boulard, 1882, p. 22, also Priestley,
1775, upon “Miscellaneous Discoveries,” likewise “Nouv. Biog.
Générale” (Hœfer), Vol. VI. p. 772; “La Grande Encycl.,” Vol.
VII. p. 454; “Journal des Sçavans,” Vol. LXIII for 1718, p. 485;
_Phil. Trans._ for 1745, Vol. XLIII. p. 419, and for 1749, Vol.
XLVI. p. 189; also Hutton’s abridgments, Vol. IX. pp. 127, 681;
and J. Martyn’s abridgments, Vol. X. part ii. pp. 277, 329.
=A.D. 1739.=--Desaguliers (Jean Theophile), chaplain to his Grace
the Duke of Chandos, gives an account of his first experiments on the
phenomena of electricity at pp. 186, 193, 196, 198, 200, 209, 634, 637,
638 and 661 of Vol. XLI of the _Phil. Trans._ for 1739. Some of
these experiments were made on the 15th of April, 1738, at H.R.H. the
Prince of Wales’ house at Cliefden.
He was the first to divide bodies into “electrics,” or non-conductors,
and “non-electrics,” or conductors. He ranked pure _air_ amongst
his electrics (Tyndall, Lecture I) and stated that “cold air in frosty
weather, when vapours rise least of all, is preferable for electrical
purposes to warm air in summer, when the heat raises the vapours”
(_Phil. Trans._, John Martyn abridgment, Vol. VIII. p. 437).
It was Desaguliers who announced that he could render bars of iron
magnetic, either by striking them sharply against the ground while in
a vertical position or by striking them with a hammer when placed at
right angles to the magnetic meridian.
His “Dissertation Concerning Electricity” London, 1742, which won for
him the grand prize of the Bordeaux Academy, is said to be the second
work on the subject published in the English language, the first
having been Boyle’s “Mechanical Origin and Production of Electricity,”
mentioned at A.D. 1675.
Desaguliers was the second to receive the Copley medal, it having been
previously bestowed by the Royal Society only upon Stephen Grey, who
obtained it in 1731 and 1732 for his “New Electrical Experiments.” The
list of recipients of this distinguished honour, given by C. R. Weld
at p. 385, Vol. I of the “History of the Royal Society,” shows that
Desaguliers received _three_ Copley medals; these were awarded him
during the years 1734, 1736 and 1741, for his “Experiments in Natural
Philosophy.” John Canton was given two of the medals, in 1751 and 1764,
the only other electrician similarly favoured being Michael Faraday,
who received them during the years 1832 and 1838, while Sir Humphry
Davy is credited with only one, conferred upon him in 1805.
“Can Britain ...
... Permit the weeping muse to tell
How poor neglected Desaguliers fell?
How he, who taught two gracious kings to view,
All Boyle ennobled, and all Bacon knew,
Died in a cell, without a friend to save,
Without a guinea, and without a grave?”
Cawthorn, “Vanity of Human Enjoyments,” V. 147–154.
In the year 1742, Desaguliers received the prize of the _Académie
Royale de Bordeaux_ for a treatise on the electricity of bodies,
which latter was separately published at the time in a quarto volume of
twenty-eight pages. The same Academy had previously conferred important
prizes for dissertations, upon the nature of thunder and lightning
by Louis Antoine Lozeran du Fech in 1726, upon the variations of the
magnetic needle by Nicolas Sarrabat in 1727, and also subsequently
decreed similar awards, to Laurent Béraud for an essay on magnets in
1748, to Denis Barberet for a treatise on atmospherical electricity in
1750, and to Samuel Theodor Quellmalz for a dissertation on medical
electricity in 1753.
REFERENCES.--_Phil. Trans._, Vol. XL. p. 385; Vol. XLII. pp.
14, 140; also the following abridgments: Hutton, Vol. VIII. pp.
246–248, 340, 346, 350–358, 470–474, 479, 546, 584; John Martyn,
Vol. VIII. part ii. pp. 419, 422–444, 740. Very interesting
reading is afforded by M. Desaguliers through the observations
he made on the magnets having more poles than two. These will
be found recorded in _Phil. Trans._ for 1738, p. 383 and in
Hutton’s abridgments, Vol. VIII. p. 246; Thomson, “Hist. Roy.
Soc.,” 1812, pp. 433, 434; “Gen. Biog. Dict.,” Alex. Chalmers,
London, 1811, Vol. XI. pp. 489–493.
=A.D. 1740.=--Celsius (Anders), who filled the chair of astronomy at
Upsal, is first to point out the great utility of making simultaneous
observations over a large extent of territory and at widely different
points. He states (_Svenska Vetenskaps Academiens Handlingar_ for 1740,
p. 44) that a simultaneity in certain extraordinary perturbations,
which had caused a horary influence on the course of the magnetic
needle at Upsal and at London, afforded proof “that the cause of these
disturbances is extended over considerable portions of the earth’s
surface, and is not dependent upon accidental local actions.”
In the following year (1741), Olav Hiörter, who was Celsius’ assistant,
discovered and measured the influence of polar light on magnetic
variation. His observations were subsequently carried on in conjunction
with Celsius, and were improved upon by Wargentin (A.D. 1750)
and by Cassini (A.D. 1782–1791).
REFERENCES.--Walker, “Ter. and Cos. Magnetism,” p. 116; also
Humboldt, “Cosmos,” _re_ “Magnetic Disturbances,” and Vol. II.
p. 438, of Weld’s “History of the Royal Society.”
=A.D. 1742.=--Gordon (Andreas), a Scotch Benedictine monk (1712–1757),
Professor of Philosophy at Erfurt, abandons the use of glass globes
(Newton, at A.D. 1675 and Hauksbee, at A.D. 1705), and is the first
to employ a glass cylinder, the better to develop electricity. His
cylinder, eight inches long and four inches wide, is made to turn by
means of a bow with such rapidity that it attains 680 revolutions per
minute.
Priestley says (“Discovery of Germans,” Part I. period vii.) that
Gordon “increased the electric sparks to such a degree that they were
felt from a man’s head to his foot, so that a person could hardly
take them without falling down with giddiness; and small birds were
killed by them. This he effected by conveying electricity, with iron
wires, to the distance of 200 ells (about 250 yards) from the place of
excitation.”
REFERENCES.--_Dantzig Memoirs_, Vol. II. pp. 358, 359, and
Nollet, “Recherches,” etc., p. 172. See also Gordon’s “Phenomena
Electricitatis Exposita,” Erford, 1744 and 1746; “Philosophia,”
1745; “Tentamen ... Electricitatis,” 1745; “Versuche ... einer
Electricität.,” 1745–1746.
=A.D. 1743.=--Hausen (Christian Augustus), Professor of Mathematics at
Leipzig, publishes his “Novi profectus in historia electricitatis,” and
is the first to revive the use of the glass globe introduced by Newton
(A.D. 1675) and employed with great effect by Hauksbee (A.D. 1705).
In Watson’s “Expériences et observations sur l’électricité,” is shown
an electrical machine constructed by Hausen and differing but slightly
from the one alluded to herein at A.D. 1705 as made for M.
Wolfius. In this illustration a lady is pressing her hand against the
glass globe, which is being rotated rapidly, thus developing upon its
surface the vitreous electricity, while the resinous electricity passes
through her body to the earth. The young man who is suspended and
insulated by silken cords, represents the prime conductor introduced
by Prof. Boze (A.D. 1738). The vitreous electricity passes
from the surface of the glass globe, through his feet and entire body,
and is communicated by his hand to the young girl, who stands upon a
large section of resin, and is able to attract small parcels of gold
leaf by means of the electric fluid. Another machine, taken from the
same French work (originally published at Paris in 1748), is said to
have been at that time much in use throughout Holland and principally
at Amsterdam. The man rotates a glass globe, against which the operator
presses his hand, and the electricity is conveyed through the metallic
rod supported by silk-covered stands and held by a third party, who is
igniting spirits in the manner indicated at the A.D. 1744 date.
REFERENCE.--_Dantzig Memoirs_, Vol. I. pp. 278, 279.
=A.D. 1743.=--Boerhaave--Boerhaaven--(Hermann), illustrious
physician, mathematician and natural philosopher (1668–1738), who
held the chairs of theoretical medicine, practical medicine, botany
and chemistry at the University of Leyden, F.R.S. and member French
Academy of Sciences, writes an Essay on the virtue of Magnetical Cures,
of which there were subsequently many editions and translations in
different languages.
One of his biographers calls him “the Galen, the Ibn Sina, the Fernel
of his age.” Another remarks that he was, perhaps, the greatest
physician of modern times: “A man who, when we contemplate his genius,
his erudition, the singular variety of his talents, his unfeigned
piety, his spotless character, and the impress which he left not only
on contemporaneous practice, but on that of succeeding generations,
stands forth as one of the brightest names on the page of medical
history, and may be quoted as an example not only to physicians, but
to mankind at large. No professor was ever attended, in public as well
as at private lectures, by so great a number of students, from such
distant and different parts, for so many years successively; none heard
him without conceiving a veneration for his person, at the same time
that they expressed their surprise at his prodigious attainments; and
it may be justly affirmed, that none in so private a station ever
attracted a more universal esteem.”
REFERENCES.--“Biographica Philosophica,” Benj. Martin, London,
1764, pp. 478–483; “Eloge de Boerhaave,” by Maty, Leyde, 1747,
and by Fontenelle, 1763, T. VI; his life, written by Dr. Wm.
Burton, London, 1736; Van Swinden, “Recueil,” etc., La Haye,
1784, Vol. II. p. 354, note; “La Grande Encyclopédie,” Tome VII.
p. 42; “Biographie Générale,” Tome VI. pp. 352–357; “Biographie
Universelle,” Vol. IV. pp. 529–555; Ninth “Encycl. Britannica,”
Vol. III. p. 854; “Histoire Philosophique de la Médecine,”
Etienne Tourtelle, Paris, An. XII. (1807), Vol. II. pp. 404–446;
“Bibl. Britan.” (Authors), Rob. Watt, Edinburgh, 1824, Vol.
I. p. 127; “The Edinburgh Encyclopædia,” 1830, Vol. III. pp.
628–630 or the 1813 ed., Vol. III. pp. 612–614; G. A. Pritzel,
“Thesaurus Literaturæ Botanicæ,” Lipsiæ, 1851, p. 26.
=A.D. 1744.=--Ludolf--Leudolff--(Christian Friedrich), of Berlin,
first exhibits, January 23, the ignition of inflammable substances
by the electric spark. This he does in the presence of hundreds of
spectators, on the occasion of the opening of the Royal Academy of
Sciences by Frederick the Great of Prussia, when fire is set to
sulphuric ether through a spark from the sword of one of the court
cavaliers (see notes on Tyndall’s second lecture, 1876, p. 80).
It was likewise at this period Ludolf the younger demonstrated that the
luminous barometer is made perfectly electrical by the motion of the
quicksilver, first attracting and then repelling bits of paper, etc.,
suspended by the side of the tube, when it was enclosed in another tube
out of which the air was extracted (_Dantzig Memoirs_, Vol. III. p.
495).
=A.D. 1744–1745.=--Waitz (Jacob Siegismund von), a German electrician,
writes three essays in Dutch and one in French, and is given the prize
of fifty ducats proposed by the Berlin Academy of Sciences for the
best dissertation on the subject of electricity. In the following
year he makes experiments, with Etienne François du Tour, to show the
destruction of electricity by flame, and, later on, with Prof. Georg
Erhard Hamberger, he proves conclusively that the motion of quicksilver
in a glass vessel out of which the air is extracted has the power of
moving light bodies. Jean Nicolas Sebastien Allamand subsequently found
that it was immaterial whether the vessel had air in it or not.
REFERENCES.--Tyndall’s Notes on Lecture II, also _Dantzig
Memoirs_, Vol. II. pp. 380, 426, and M. du Tour’s “Recherches
sur les Différents Mouvements de la Matière Electrique,” Paris,
1760.
=A.D. 1745.=--Kratzenstein (Christian Gottlieb), Professor of
Medicine at Halle, author of “Versuch einer Erklarung,” etc., and of
“Theoria Electricitatis,” etc., is said to have first successfully
employed electricity in the relief of sprains, malformations, etc. He
observed that a man’s pulse, which had beat eighty in a second before
he was electrified, immediately after beat eighty-eight, and was soon
increased to ninety-six.
Kratzenstein is reported (Mary Somerville, “Physical Sciences,” Section
XVII.) to have made instruments which articulated many letters, words
and even sentences, and somewhat similar in construction to those
alluded to at A.D. 1620 (De Bergerac), and A.D. 1641 (John Wilkins),
some of which may truly be said to strongly suggest the modern
phonograph.
Albertus Magnus constructed, after thirty years of experimentation, a
curious machine which sent forth distinct vocal sounds, at which the
very learned scholastic philosopher Saint Thomas Aquinas (“Angel of the
Schools”) was so much terrified that he struck the contrivance with his
stick and broke it. Bishop Wilkins alludes to this machine as well as
to a brazen head devised by Friar Bacon, which could be made to utter
certain words (“Journal des Savants” for 1899, and J. S. Brewer, “F.
Rog. Bacon,” 1859, p. xci; also, “How Fryer Bacon made a Brasen Head to
Speake,” at pp. 13–14 of the “Famous Historie of Fryer Bacon published
at London for Francis Groue”).
Incidentally, it may be mentioned that Wolfgang von Kempelen, Aulic
Counsellor to the Royal Chamber of the Domains of the Emperor of
Germany, after witnessing some magnetic games shown to the Empress
Maria Theresa at Vienna, constructed, during the year 1778, a speaking
machine which “gave sounds as of a child three or four years of age,
uttering distinct syllables and words” (Wm. Whewell, “Hist. of the
Inductive Sciences,” Vol. II. chap. vi.; J. E. Montucla, “Hist. des
Mathém,” Vol. III. p. 813).
_La Nature_, Paris, May 6, 1905, pp. 353–354, illustrates the
_speaking head_ of l’Abbé Mical presented by him to the French
Academy of Sciences July 2, 1783, and alludes to those of Albertus
Magnus, Wolfgang von Kempelen, C. G. Kratzenstein, etc.
Two more curious productions, in pretty much the same line as
Bergerac’s, can, with equal propriety, be inserted here.
The first is taken from the April number, 1632, of the _Courier
Véritable_, a little monthly publication in which novel fancies were
frequently aired: “Captain Vosterloch has returned from his voyage to
the southern lands, which he started on two years and a half ago, by
order of the States-General. He tells us, among other things, that
in passing through a strait below Magellan’s, he landed in a country
where Nature has furnished men with a kind of sponge which holds sounds
and articulations as our sponges hold liquids. So, when they wish to
dispatch a message to a distance, they speak to one of the sponges, and
then send it to their friends. They, receiving the sponges, take them
up gently and press out the words that have been spoken into them, and
learn by this admirable means all that their correspondents desire them
to know.”
The second is the production of one Thomas Ward, theological poet, who
was born in 1640 and died in 1704. In the second canto of one of his
poems occur these words:
“As Walchius could words imprison
In hollow canes so they, by reason,
Judgment and great dexterity,
Can bottle words as well as he;
And can from place to place convey them,
Till, when they please, the _reed_ shall say them;
Will suddenly the same discharge,
And hail-shot syllables at large
Will fly intelligibly out
Into the ears of all about:
So that the _auditors_ may gain
Their meaning from the breach of cane.”
REFERENCES.--Priestley, “History,” etc., 1775, p. 374, and
_Dantzig Memoirs_, Vol. I. p. 294.
=A.D. 1745.=--Grummert (Gottfried Heinrich), of Biala, Poland, first
observes the return of the electric light _in vacuo_. In order to
ascertain whether an exhausted tube would give light when it was
electrified, as well as when it was excited, he presented one eight
inches long and a third of an inch wide, to the electrified conductor,
and was surprised to find the light dart very vividly along the entire
length of the tube. He likewise observed that some time after the tube
had been presented to the conductor, and exposed to nothing but the
air, it gave light again without being brought to an electrified body
(see _Dantzig Memoirs_, Vol. I. p. 417).
=A.D. 1745.=--Dr. Miles (Rev. Henry), of Tooting, D.D. (1698–1763)
reads, March 7, before the English Royal Society a paper indicating
the possibility of kindling phosphorus by applying to it an excited
electric without the approach of a conducting body. This gentleman’s
tube happening to be in excellent order upon this occasion, he
observed, and doubtless was the first to notice, _pencils of luminous
rays_, which he called _coruscations_, darting from the tube without
the aid of any conductor approaching it.
In a paper which Dr. Miles read before the same Society on the 25th
of January, 1746, he gave an account of other equally interesting
experiments, one of which was the kindling of ordinary lamp spirits
with a piece of black sealing wax excited by dry flannel or white and
brown paper.
REFERENCES.--“Dict. Nat. Biog.,” Sidney Lee, Vol. XXXVII. p.
378; _Phil. Trans._, Vol. XLIII. pp. 290, 441; Vol. XLIV. pp.
27, 53, 78, 158, and the following abridgments: Hutton, Vol.
IX. pp. 107, 136, 191, 198, 207, 213, 232; John Martyn, Vol. X.
part ii. pp. 272, 277, 317, 319, 322–323, 325.
=A.D. 1745.=--This period was to witness a discovery which, according
to Professor Tyndall, “_throws all former ones in the shade_,” and
which Dr. Priestley calls “_the most surprising yet made in the whole
business of electricity_.” This was the accumulation of the electric
power in a glass phial, called the Leyden jar after the name of the
place where the discovery was made. It was first announced in a letter
to Von Kleist, dean of the cathedral of Kamin--Cammin--in Pomerania,
dated the 4th of November, 1745, and addressed to Dr. Lieberkühn, who
communicated it to the Berlin Academy. The following is an extract:
“When a nail or a piece of thick brass wire is put into a small
apothecary’s phial and electrified, remarkable effects follow; but
the phial must be very dry or warm; I commonly rub it over beforehand
with a finger, on which I put some pounded chalk. If a little mercury,
or a few drops of spirit of wine, be put into it, the experiment
succeeds the better. As soon as this phial and nail are removed from
the electrifying glass, or the prime conductor to which it has been
exposed is taken away, it throws out a pencil of flame so long that,
with this burning machine in my hand, I have taken above sixty steps in
walking about my room; when it is electrified strongly I can take it
into another room and there fire spirits of wine with it. If while it
is electrifying I put my finger, or a piece of gold which I hold in my
hand, to the nail, I receive a shock which stuns my arms and shoulders.”
It is said that Cunæus, rich burgess of Leyden, accidentally made
the same discovery in January 1746. It appears that Pieter Van
Musschenbroek, the celebrated professor, while experimenting with his
colleagues, Cunæus and Allamand, observed that excited bodies soon
lost their electricity in the open air, attributable to the vapours
and effluvia carried in the atmosphere, and he conceived the idea that
the electricity might be retained by surrounding the excited bodies
with others that did not conduct electricity. For this purpose he
chose water, the most readily procured non-electric, and placed some
in a glass bottle. No important results were obtained until Cunæus,
who was holding the bottle, attempted to withdraw the wire which
connected with the conductor of a powerful electric machine. He at once
received a severe shock in his arms and breast, as did also the others
upon renewing the experiment. In giving an account of it to the great
scientist, René de Réaumur, Musschenbroek remarked: “For the whole
kingdom of France, I would not take a second shock.” Allamand states
that when he himself took the shock “he lost the use of his breath for
some minutes, and then felt so intense a pain along his right arm that
he feared permanent injury from it.”
In his “Cours Elémentaire de Physique,” Musschenbroek describes one
of the peculiar electrical machines then being constructed by the
well-known London instrument maker, George Adams, and a cut of it can
be seen at p. 353, Vol. I. of the translation made by Sigaud de la
Fond at Paris during 1769. Another of Adams’ machines is described and
illustrated at p. 126 of the French translation of Cavallo’s “Complete
Treatise,” published at Paris in 1785.
The invention of the Leyden jar is claimed with equal pertinacity for
Kleist, Musschenbroek and Cunæus. While it is necessarily conceded
that Von Kleist first published his discovery, it cannot be denied
that his explanation of it is so obscure as, for the time, to have
been of no practical use to others. It is stated by Priestley:
“Notwithstanding Mr. Kleist immediately communicated an account of this
famous experiment (which indeed it is evident he has but imperfectly
described) to Mr. Winckler, at Leipzig, Mr. Swiettiki, of Denmark, Mr.
Kruger, of Halle, and to the professors of the Academy of Lignitz,
as well as to Dr. Lieberkühn, of Berlin, above mentioned, they all
returned him word that the experiment did not succeed with them. Mr.
Gralath, of Dantzig, was the first with whom it answered; but this was
not till after several fruitless trials, and after receiving further
instructions from the inventor. The Abbé Nollet had information of
this discovery, and, in consequence of it says, in a letter to Mr.
Samuel Wolfe, of the Society of Dantzig, dated March 9, 1746, that the
experiment at Leyden was upon principles similar to that made with
a phial half full of water and a nail dipped in it; and that this
discovery would have been called the Dantzig experiment if it had not
happened to have got the name of that of Leyden.”
In the thirty-eighth volume of the _Philosophical Transactions_,
No. 432, p. 297, is given an abstract of a letter (dated Utrecht,
January 15, 1733, O. S.), from Petrus Van Musschenbroek, M.D., F.R.S.,
to Dr. J. T. Desaguliers, concerning experiments made on the Indian
Magnetic Sand, chiefly gathered along the seashore in Persia. After
detailing his many observations, Van Musschenbroek asks: “And, now,
what can this _sand_ be? Is it an imperfect magnet, or Subtile
Powder of it, which, when it is grown up into a greater lump, makes
the vulgar Loadstones? So I conjectured at first; but when I found by
experience that common Loadstones, exposed to the fire, according to
some of the methods above-mention’d, did rather lose of their force
than gain, I alter’d my opinion; and now confess that I have not yet
penetrated into the knowledge of the nature of this matter.”
REFERENCES.--Dalibard, “Histoire Abrégée,” p. 33; _Dantzig
Memoirs_, Vol. I. pp. 407, 409, 411; Johann Gottlob Kruger,
“Dissert. de Elect.,” Helmstadt, 1756 (Poggendorff, I. p. 1323);
Priestley, 1777, “The Hist. and Pres. State of Electricity,”
pp. 82–84; Opuscoli Scelti, 4to, xviii, 55; Pierre Massuet,
“Essais,” Leide, 1751; Musschenbroek’s “Epitome elementorum,”
etc., 1726, “Tentamina Experimentorum Naturalium,” 1731,
and his “Disertatio Physica experimentalis de Magnete,” as
well as his “Elementa Physicæ,” 1734, and the “Introductio
ad Philosophiam Naturalem,” 1762, the last-named two works
being greatly amplified editions of the “Epitome.” For
Musschenbroek--Musschenbrock--consult also _Phil. Trans._, Vol.
XXXII. p. 370; Vol. XXXVII. pp. 357, 408, also the following
abridgments: Baddam, 1745, Vol. VIII. p. 42; Reid and Gray, Vol.
VI. p. 161 (Musschenbroek to Desaguliers); Hutton, Vol. VII. pp.
105, 647 (magnetic sand); Eames and Martyn, Vol. VI. part ii. p.
255; John Martyn, Vol. VIII. p. 737 (magnetic sand). For this
magnetic sand, consult also Mr. Butterfield’s article in _Phil.
Trans._ for 1698, p. 336 and in the abridgments of Hutton, Vol.
IV. p. 310.
=A.D. 1745.=--Watson (William), M.D., F.R.S., an eminent English
scientist, bears “the most distinguished name in this period of the
history of electricity.” His first letters, treating of this science,
are addressed to the Royal Society between March 28 and October 24,
1745, and, on the 6th of February and the 30th of October, 1746, he
communicated other similar papers to the same Society, all which, like
his subsequent treatises, are to be found in the _Philosophical
Transactions_.
Dr. Watson, like most scientists at the time, made numerous experiments
with the Leyden jar, and he was the first to observe the flash of light
attending its discharge. He says: “When the phial is well electrified,
and you apply your hand thereto, you see the fire flash from the
outside of the glass wherever you touch it, and it crackles in your
hand.” It is to him that we owe the double coating of the jar, as well
as the _plus_ and _minus_ of electricity.
He also shows conclusively that glass globes and tubes do not possess
in themselves the electrical power, but only serve “as the first movers
or determiners of that power,” and he also proves that the electric
fluid takes the shortest course, passing through the substance of
the best medium of connection and not along its surface. This, he
demonstrated by discharging a phial through a wire covered with a
mixture of wax and resin.
In order to ascertain the velocity of the electric fluid from the
Leyden phial and the distance at which it could be transmitted (John
Wood, at A.D. 1726), Watson directed a series of experiments
upon a very grand scale, with the assistance of Martin Folkes,
President of the Royal Society, Lord Charles Cavendish, Dr. Bevis, Mr.
Graham, Dr. Birch, Peter Daval and Messrs. Trembley, Ellicott, Robins
and Short. On the 14th and 18th of July, 1747, they experimented upon
a wire carrying the electricity from the Thames bank at Lambeth to
the opposite bank at Westminster, across Westminster Bridge, and, on
the 24th of July, at the New River, Stoke Newington, they sent a shock
through 800 feet of water and 2000 feet of land, as well as through
2800 feet of land and 8000 feet of water. Other experiments followed
on the 28th of July and the 5th of August, as well as on the 14th of
August of the same year, proving the instantaneous transmission of the
fluid; while a year later, August 5, 1748, additional observations
were made, through 12,276 feet of wire, at Shooter’s Hill, showing
again that the time occupied in the passage of the electricity was
“altogether inappreciable.” Regarding these experiments, Prof.
Musschenbroek wrote to Dr. Watson, “_Magnificentissimis tuis
experimentis superasti conatus omnium_.”
Watson’s experiments were repeated, notably by Franklin, across the
Schuylkill at Philadelphia, in 1748; by Deluc, across the Lake of
Geneva, in 1749; and by Winckler, at Leipzig, in 1750. It is said
that Lemonnier (A.D. 1746) produced shocks at Paris through
12,789 feet of wire and that Bétancourt (A.D. 1795) discharged
electric jars through a distance of twenty-six miles.
To Dr. Watson is also due the first demonstration of the passage of
electricity through a vacuum. Noad tells us that he caused the spark
from his conductor to pass in the form of coruscations of a bright
silver hue through an exhausted tube three feet in length, and he
discharged a jar through a vacuum interval of ten inches in the form
of “a mass of very bright embodied fire.” These demonstrations were
repeated and varied by Canton, Smeaton and Wilson.
His experiments in firing gunpowder, hydrogen, etc., by the electric
spark, are detailed at p. 78 of Priestley’s “History,” etc., London,
1775.
Watson was rewarded with the Copley medal for his researches in
electricity, which brought him also honorary degrees from two German
universities. He was knighted in 1786, one year before his death.
REFERENCES.--“Watson’s Experiments and Observations on
Electricity,” 1745, also his “Account of the Experiments made
by some gentlemen of the Royal Society,” etc., 1748; _Phil.
Trans._, Vol. XLIII. p. 481; Vol. XLIV. pp. 41, 388, 695,
704; Vol. XLV. pp. 49–120, 491–496; Vol. XLVI. p. 348; Vol.
XLVII. pp. 202, 236, 362, 567; Vol. XLVIII. p. 765; Vol. LI.
p. 394 (lyncurium of the ancients); Vol. LIII. p. 10; also the
following abridgments: Hutton, Vol. IX. pp. 151, 195, 308, 368,
408, 410, 440, 553; Vol. X. pp. 12, 189, 197, 227, 233, 242,
303, 372–379, 525; Vol. XI. p. 419 (lyncurium of the ancients),
580, 660, 679; Vol. XII. p. 127; John Martyn, Vol. X. part
ii. pp. 279–280, 290, 294, 329, 339, 347, 368, 407, 410. See
likewise, _Scientific American Supplement_ of Oct. 5, 1889, No.
718, pp. 11, 471, for an interesting engraving of Dr. Watson’s
experiment made through the water of the Thames, as well as for
a detailed account of Lemonnier’s experiment above referred to.
For Mr. A. Trembley, consult _Phil. Trans._, Vol. XLIV. p. 58,
and John Martyn’s abridgments, Vol. X. part ii. p. 321.
=A.D. 1746.=--Lemonnier (Pierre Claude Charles), a distinguished
savant, who was member of the French Academy as adjunct geometrician
before he had attained his twenty-first year and became foreign member
of the English Royal Society three years later, was the first scientist
who drew electricity from the narrow domain of the laboratory.
He confirmed the result previously obtained by Grey (A.D.
1720) that electric attraction is not proportioned to the mass or
quantity of matter in bodies, but only to the extent of their surface,
length having greater effect than breadth (_Phil. Trans._, Vol.
XLIV for 1746, p. 290; Snow Harris, “Treatise on Frict. Elect.,”
London, 1867, p. 239, and “Hist. de l’Acad.,” 1746). He found that an
anvil weighing two hundred pounds gives but an inconsiderable spark,
while the spark from a tin speaking-trumpet eight or nine feet long,
but weighing only ten pounds, is almost equal to the shock of the
Leyden phial. A solid ball of lead, four inches in diameter, gives a
spark of the same force as that obtained from a thin piece of lead of
like superficies bent in the form of a hoop. He took a thin and long
piece of lead, and noticed that when it was electrified in its whole
length it gave a very strong spark, but a very small one when it was
rolled into a lump (_Ac. Par._, 1746, M. p. 369). It had likewise
been shown by Le Roi and D’Arcy that a hollow sphere accepted the same
charge when empty as when filled with mercury, which latter increased
its weight sixtyfold; all proving the influence of _surface_ as
distinguished from that of mass (Tyndall, Notes on Lecture IV).
Lemonnier discovered that electricity is ever present in the
atmosphere, that it daily increases in quantity from sunrise till about
three or four o’clock in the afternoon, diminishing till the fall of
dew, when it once more increases for a while, and finally diminishes
again before midnight, when it becomes insensible. He observed a
continual diminution of electricity as the rain began to fall, and he
says: “When the wire was surrounded with drops of rain, it was observed
that only some of them were electrical, which was remarkable by the
conic figure they had; whilst the others remained round as before.
It was also perceived that the electrical and non-electrical drops
succeeded almost alternately; this made us call to mind a very singular
phenomenon which happened some years before, to five peasants who were
passing through a cornfield, near Frankfort upon the Oder, during a
thunderstorm; when the lightning killed the first the third and the
fifth of them, without injuring the second or the fourth” (_Phil.
Trans._, Vol. XLVII. p. 550).
REFERENCES.--Le Monnier, “Lois du Magnétisme,” Paris, 1776–1778;
_Phil. Trans._, Vol. XLIV. p. 247; Vol. XLVIII. part i. p.
203; “Journal des Sçavans,” Vol. CXII for 1737, p. 73; also
Hutton’s abridgments, Vol. IX. pp. 275, 308, 368, 591 (biogr.);
John Martyn’s abridgments, Vol. X. part ii. pp. 329–348;
“Philosophical Magazine,” Vol. VI. for 1800, p. 181, “Some
Account of the Late P. C. Le Monnier,” 1715–1799; “Mémoires de
l’Institut Nat. des Sc. et des Arts,” Hist. An. IX. p. 101;
_Mémoires de l’Acad. Royale des Sciences_, 1746, pp. 14–24, 447,
671–696; 1752, Tome I. pp. 9–17, Tome II. 233–243, 346–362;
1770, p. 459; Bertholon, “Elec. du Corps Humain,” 1786, Vol.
I. pp. 10–14; Harris, “Frict. Elec.,” p. 239; _Sc. American
Supplement_, for Oct. 5, 1889, No. 718, pp. 11, 471. See also
reports of the experiments of G. B. Beccaria, G. F. Gardini (“De
inflexu,” etc., ss. 50, 51), Andrew Crosse and others at “Bibl.
Britan. Sc. et Arts,” 1814, Vol. LVI. p. 524.
=A.D. 1746.=--Bevis (John), English astronomer and Secretary of
the Royal Society, first suggested to Dr. Watson the external coating
of the Leyden jar with tinfoil or sheet-lead, and was likewise the
first to observe that the force of the charge increases as larger jars
are employed, but not in proportion to the quantity of water they
contain. As water only played the part of a conductor, he rightly
thought that metal would do equally well, and he therefore filled
three jars with leaden shot instead of with water. When the metallic
connection was made it was found that the discharge from three jars was
greater than that from two and the discharge from two much greater than
that from one. This showed that the seat of the electric force is the
surface of the metal and the glass, and proves that the force of the
charge is in proportion to the quantity of coated surface.
Thus to Dr. Bevis belongs the credit of having constructed the first
electric battery, although the honour has been claimed by the friends
of Daniel Gralath (A.D. 1747).
REFERENCES.--_Phil. Trans._, abridged, Vol. X. pp. 374, 377;
Wilson, “Treatise,” London, 1752, Prop. XVII. p. 107.
=A.D. 1746.=--Le Cat (Claude Nicolas), a physician of Rouen, observed,
when suspending several pieces of leaf gold at his conductor, that they
hung at different distances according to their sizes, the smallest
pieces placing themselves nearest the conductor and the largest
farthest from it.
Le Cat (1700–1768) became celebrated for his surgical operations and
succeeded in carrying off all the first prizes offered by the Royal
Academy of Surgeons between the years 1734 and 1738 inclusively.
Consult his different works named at p. 292 of Ronalds’ “Catalogue”;
“Histoire de l’Electricité,” pp. 84 and 85; “Biographie Générale,” Vol.
XXX. pp. 179–182.
=A.D. 1746.=--Maimbray (M.), of Edinburgh, electrified two myrtle
trees, during the entire month of October 1746, and found that they put
forth small branches and blossoms sooner than other shrubs of the same
kind which had not been electrified. This result was confirmed by the
Abbé Nollet, who filled two pots with vegetating seeds and found that
the pot which he had constantly electrified for fifteen consecutive
days put forth earlier sprouts as well as more numerous and longer
shoots than did the other.
Like experiments were at the same time carried on with equal success
by M. Jallabert and M. Boze, as well as by the Abbé Menon, Principal
of the College of Bueil at Angers, France. The last named also found
that electricity increases the insensible perspiration of animals.
He chose cats, pigeons and chaffinches, and observed after they were
electrified, that one cat was sixty-five or seventy grains lighter than
the other, the pigeon from thirty-five to thirty-eight grains, and the
chaffinch had lost six or seven grains. He also electrified a young
person between the ages of twenty and thirty, for five hours and found
a loss in weight of several ounces.
With reference to the effect of electricity on different varieties of
growing plants, a paper in Boston not long ago published the following:
“In the last few years some very interesting experiments in
gardening by electricity have been made by Prof. Selim Lemström,
of the University of Helsingfors. These have been carried out
both upon the potted plants in the hot-house and upon plants in
the open field, the insulated wires in the latter case being
stretched upon poles over the plot of ground, and provided
with a point for each square metre of area. The current has
been supplied by Holtz machines run from eight to eighteen
hours daily, the positive pole being connected with the network
of wires and the negative with a zinc plate buried in the
ground. The electric influence was scarcely perceptible in
the growing plants, but was very marked in the yield of many
species, especially of barley and wheat, of which the crop was
increased by half in some cases. In the hot-house the maturity
of strawberries was greatly advanced. The results have shown
that plants may be divided into two groups: one, the development
of which is favoured by electricity, comprising wheat, rye,
barley, oats, red and white beets, parsnips, potatoes,
celeriac, beans, raspberries, strawberries and leeks; and the
other, whose development is more or less interfered with by
electricity, including peas, carrots, kohlrabi, rutabagas,
turnips, white cabbages and tobacco. The more fertile the soil,
and consequently the more vigorous the vegetation, the greater
has been the excess of the crop under electric influence. Prof.
Lemström’s experiments up to 1887 were carried on in Finland,
but he has since repeated his work in France, and demonstrated
that the electric influence is the same in any climate, though
likely to be injurious under a scorching sun.”
REFERENCES.--Nollet, “Recherches sur l’Electricité,” pp. 366,
382; _Phil. Trans._, abridged, Vol. X. p. 384; _Electrical
Review_, London, June 5, 1891, p. 707.
=A.D. 1746.=--Knight (Gowan or Gowin), F.R.S., an English physician,
is the first to make very powerful steel magnets. The method, which he
long succeeded in keeping secret, was described after his death, in
the _Phil. Trans._ for 1746–1747, Vol. XLIV. It consists of placing
two magnets in the same straight line, with their opposite poles close
to or very near each other, and in laying under them the bar to be
magnetized after having it tempered at a cherry-red heat. The magnets
are then drawn apart in opposite directions along the bar, so that the
south pole of one magnet passes over the north polar half, and the
north pole of the other magnet passes over the south polar half of the
bar.
This was how Dr. Knight made the bars of the two great magnets of
the Royal Society. Each magnet contained two hundred and forty bars,
fifteen inches long, one inch wide and half an inch thick. Dr. Robison
described, in 1800, the effect of pressing together the dissimilar
poles of the two magnets, and, thirty years later, Prof. Faraday, upon
placing a soft iron cylinder, one foot long and three-quarters of an
inch in diameter, across the dissimilar poles, found that he required a
force of one hundred pounds to break down the attractive power.
Previously to Dr. Knight’s discovery, the method of making artificial
magnets most in use was by simply rubbing the bar to be magnetized upon
one of the poles of a natural magnet in a plane at right angles to the
line joining its two poles.
Another secret of Dr. Knight was also, after his death, made known to
the Royal Society by its secretary, Mr. Benjamin Wilson. It was the
mode of making artificial paste magnets. He collected a large quantity
of iron filings, which he cleansed and made into a fine powder under
water and afterward dried and mixed, preferably with linseed oil. This
was baked into cakes, which were magnetized by placing them between the
ends of his magazine of artificial magnets.
To Dr. Knight was given the first English patent in the Class of
Electricity and Magnetism. It bears date June 10, 1766, No. 850, and is
for the construction of “Compasses so as to prevent them being affected
by the motion of the ship,” etc.
REFERENCES.--_Phil. Trans._, Vol. XLIII. pp. 161, 361; Vol.
XLIV. p. 656; Vol. XLIX. p. 51; Vol. LXVI. p. 591; C. R. Weld,
“Hist. of Roy. Soc.,” Vol. I. p. 511; Noad, “Manual,” 1859, p.
593; Sturgeon, “Sc. Researches,” Bury, 1850, p. 249; also the
abridgments by Hutton, Vol. IX. pp. 71, 74, 122, 390 (Folkes),
653; Vol. X. pp. 64, 67; Vol. XIV. pp. 117, 480; and by John
Martyn, Vol. X. part ii. pp. 678–698.
=A.D. 1746.=--Gravesande (Wilhelm Jacob), celebrated Dutch
mathematician and natural philosopher (1688–1742), whose family name
was Storen Van ’Sgravesande, is the author of “Eléments de physique
démontrés mathématiquement ... ou introduction à la philosophie
Newtonienne,” which was translated from the Latin and published at
Leyden in 1746.
At p. 87 of the second volume of the last-named work he gives a
description of an electrical machine constructed on the plan of that
of Hauksbee. It consisted merely of a crystal globe, which was mounted
upon a copper stand, and against which was pressed the hand of the
operator while it was made to revolve rapidly by means of a large wheel.
Gravesande taught publicly on the Continent the philosophy of Newton,
and, by so doing, was one of the first to bring about a revolution
in the domain of physical sciences generally. His original “Physices
Elementa Mathematica,” as well as his “Philosophiæ Newtonianæ,” etc.,
and “Introductio ad Philosophiam,” etc., were respectively published at
Leyden in 1720, 1723 and 1736.
REFERENCE.--Houzeau et Lancaster, “Bibl. Générale,” Vol. II. p.
252.
=A.D. 1746.=--Nollet (Jean Antoine), a distinguished French philosopher
(1700–1770), to whom was given the title of Abbé while holding deacon’s
orders, is the first in France to make experiments with the Leyden jar.
While in Paris he applied himself to electrical studies in company with
Charles Dufay (already noticed at A.D. 1733), and made such ingenious
experiments that René de Réaumur allowed him the free use of his
extensive apparatus and laboratory. During the month of April 1746, he
transmitted, in the presence of the French King, an electrical shock
from a small phial through a chain of one hundred and eighty of the
Royal Guards, and at the Carthusian Convent, not long afterward, he
sent a shock through a line of monks stretched a distance of over a
mile, causing them all to experience instantaneously the same sensation.
Nollet’s work, “Essai sur l’électricité des corps,” was originally
published at Paris in 1746. He was the first to observe that pointed
bodies electrified give out streams of light (the smallest points
displaying “brushes of electric light”), but that they do not exhibit
as powerful indications of electricity as are shown by blunt bodies.
He also found that glass and other non-conductors are more strongly
excited in air than _in vacuo_; that the electric spark is more diffuse
and unbroken _in vacuo_; and that an excited tube loses none of its
electricity by being placed in the focus of a concave mirror when the
sunlight is therein concentrated.
His experiments upon the evaporation of fluids by electricity, as well
as upon the electrification of capillary tubes full of water (observed
also by Boze), and upon the electrification of plants and animals, are
detailed in his “Recherches,” etc., pp. 327, 351, 354–356, while his
observations upon the electrical powers of different kinds of glass are
given in the sixth volume of the “Leçons de Physique Expérimentale,”
issued in 1764.
As has been truly said, it is no easy matter to form an adequate idea
of Nollet’s theory of electricity, which was opposed at the time by
almost all the eminent electrical philosophers of Europe. He asserted
that when an electric is excited, electricity flows to it from all
quarters, and when it is thus _affluent_, it drives light bodies before
it. Hence the reason why excited bodies attract. When the electricity
is _effluent_ the light bodies are of course driven from the electric,
which in that condition appears to repel. He therefore believed every
electric to be possessed of two different kinds of pores, one for the
emission of the electric matter, and the other for its reception.
Nollet is the first one who published the close relationship existing
between lightning and the electric spark. This he did during the year
1748, in the fourth volume of his “Leçons,” already alluded to and
from which the following is extracted: “If any one should undertake to
prove, as a clear consequence of the phenomenon, that thunder is in
the hands of nature what electricity is in ours--that those wonders
which we dispose at our pleasure are only imitations on a small scale
of those grand effects which terrify us, and that both depend on the
same mechanical agents ... I confess that this idea, well supported,
would please me much.... The universality of the electric matter,
the readiness of its actions, its instrumentality and its activity
in giving fire to other bodies, its property of striking bodies,
externally and internally, even to their smallest parts ... begin to
make me believe that one might, by taking electricity for the model,
form to one’s self, in regard to thunder and lightning, more perfect
and more probable ideas than hitherto proposed.”
For a memoir treating of the cause of thunder and lightning, written
by the Rev. Father de Lozeran de Fech, of Perpignan, the Bordeaux
Academy of Sciences had in 1726 awarded him its annual prize; and the
same institution conferred a similar award, in August 1750, upon M.
Bergeret, a physician of Dijon, whose memoir admitted the close analogy
between lightning and electricity.
REFERENCES.--Ronalds’ “Catalogue,” pp. 369–371; Jean Morin,
“Réplique,” Paris, 1749; A. H. Paulian, “Conjectures,” 1868;
“Abrégé des transactions philosophiques,” Vol. X. p. 336;
“Mémoires de mathématique,” etc., pour 1746, p. 22; “Journal des
Sçavans,” Vol. CXVII. for 1739, pp. 111–115, and Vol. CXLII for
1747, pp. 248–265; “Medical Electricity,” by Dr. H. Lewis Jones,
Philad., 1904, p. 2; “Mémoires de l’Acad. Royale des Sciences”
pour 1745, p. 107; 1746, p. 1; 1747, pp. 24, 102, 149, 207;
1748, p. 164; 1749, p. 444; 1753, pp. 429, 475; 1755, p. 293;
1761, p. 244; 1762, pp. 137, 270; 1764, pp. 408–409; 1766, p.
323; “Leçons,” eighth edition, Vol. IV. p. 315; _Phil. Trans._,
Vol. XLV. p. 187; Vol. XLVI. p. 368; Vol. XLVII. p. 553; also
the following abridgments: Hutton, Vol. X. pp. 20, 295, 372–379,
446 (Dr. Birch); Vol. XI. p. 580; John Martyn, Vol. X. part ii.
pp. 277–333, 382 (Folkes), 414. See the experiments of Etienne
François du Tour, “Sur la manière dont la flamme agit sur les
corps electriques,” in a letter addressed by him to Nollet in
1745, and in “Mém. de Mathém. et Phys.,” Vol. II. p. 246, Paris,
1755; also Zantedeschi and Faraday on the “Magnetic Condition of
Flame” (Faraday’s “Exper. Res.,” Vol. III. pp. 490–493).
=A.D. 1746.=--Wilson (Benjamin) (1721–1788), Secretary to the Royal
Society, writes his “Essay toward an explication of the phenomena of
Electricity deduced from the ether of Sir Isaac Newton.” In the chapter
of Priestley’s “History” treating of the Theories of Electricity, he
says: “With some, and particularly Mr. Wilson, the chief agent in all
electrical operations is Sir Isaac Newton’s ether, which is more or
less dense in all bodies in proportion to the smallness of their pores,
except that it is much denser in sulphureous and unctuous bodies. To
this ether are ascribed the principal phenomena of attraction and
repulsion, whereas the light, the smell, and other sensible qualities
of the electric fluid are referred to the grosser particles of bodies,
driven from them by the forcible action of this ether. Many phenomena
in electricity are also attempted to be explained by means of a
subtile medium, at the surface of all bodies, which is the cause of
the refraction and reflection of the rays of light, and also resist
the entrance and exit of this ether. This medium, he says, extends to
a small distance from the body, and is of the same nature with what is
called the electric fluid.[50] On the surface of conductors this medium
is rare and easily admits the passage of the electric fluid, whereas
on the surface of electrics it is dense and resists it. This medium is
rarefied by heat, which converts non-conductors into conductors.”
At pp. 71 and 88, 1746 edition, and at p. 88, Prop. XI. of the 1752
edition of this same “Essay,” Wilson says that during the year 1746
he discovered a method of giving the shock of the Leyden jar to any
particular part of the body without affecting any other portion; that
he increased the shock from the jar by plunging it into water, thereby
giving it a coating of water on the outside as high as it was filled on
the inside; and that the accumulation of electricity in the Leyden jar
is always in proportion to the thinness of the glass, the surface of
the glass and that of the non-electrics in contact with the inside and
outside thereof.
It was in this same year, 1746, that Wilson first observed the _lateral
shock_ or _return stroke_, which was not, however, explained until
Lord Mahon, third Earl of Stanhope, published his “Principles of
Electricity,” in 1779.
On the 13th of November, 1760, a paper of Mr. Wilson’s was read before
the Royal Society, in which he detailed several of his ingenious
experiments on the _plus_ and _minus_ of electricity, and showed
that these can be produced at pleasure by carefully attending to the
form of bodies, their sudden or gradual removal and the degrees of
electrifying. He had previously noticed that when two electrics are
rubbed together, the body whose substance is hardest and electric power
strongest is always electrified positively and the other negatively.
Rubbing the tourmaline and amber together he produced a _plus_
electricity on both sides of the stone and a _minus_ on the amber; but,
rubbing the diamond and the tourmaline, both sides of the tourmaline
were electrified _minus_ and the diamond _plus_. When insulated silver
and glass were rubbed, the silver became _minus_ and the glass _plus_.
He further observed that when directing a stream of air against a
tourmaline, a pane of glass or a piece of amber, these were electrified
_plus_ on both sides. Prof. Faraday subsequently showed that no
electrical effect is produced in these cases unless the air is either
damp or holds dry powders in suspension, the electricity being
produced by the friction of particles of water in the one case and
by the particles of powder in the other. Sir David Brewster, who thus
mentions the latter fact, likewise singles out two more of Mr. Wilson’s
observations, viz. that when a stick of sealing-wax is broken across or
when a dry, warm piece of wood is rent asunder, one of the separated
surfaces becomes vitreously and the other resinously electrified.
REFERENCES.--De La Rive, “Electricity,” Vol. I. p. 203; Wilson,
“Treatise on Electricity”; Wilson and Hoadley, “Observations
on a Series of Electrical Experiments”; _Phil. Trans._, Vol.
XLVIII. p. 347; Vol. XLIX. p. 682; Vol. LI. part i. pp. 83, 308,
331, part ii. p. 896; Vol. LIII. pp. 436, etc.; Vol. LXVIII.
p. 999; Vol. LXIX. p. 51; also Hutton’s abridgments; Vol. X.
p. 420; Vol. XI. pp. 15, 396, 504; Vol. XII. pp. 44, 147; Vol.
XIII. p. 374; Vol. XIV. pp. 334, 337, 458, 480; “The Electrical
Researches of the Hon. Henry Cavendish,” Cambridge, 1879, No.
125; L. E. Kaemtz, “Lehrbuch der Meteor,” Halle, 1832, Vol. II.
p. 395.
=A.D. 1746.=--Ellicott (John), of Chester, suggests a method of
estimating the exact force of the electric charge contained in the
Leyden jar by its power to raise a weight in one scale of a balance
while the other scale is held over and attracted by the electrified
body. This was the principle upon which Mr. Gralath constructed the
electrometer shown in _Dantzig Memoirs_, Vol. I. p. 525.
With reference to the experiments of Boze (A.D. 1738) and of Nollet
(A.D. 1746) made with capillary tubes, he says that the siphon,
though electrified, will only deliver the water by drops if the
basin containing the water is also electrified. He explains Nollet’s
observation, that the electric matter issues more sensibly from the
point at the extremity of the conductor, by saying that the effluvia,
in rushing from the globe along the conductor, as they approach the
point are brought nearer together, and therefore are denser there,
and if the light be owing to the density and velocity of the effluvia
it will be visible at the point and nowhere else. Ellicott’s theory
of electricity is founded upon the following data: (1) electrical
phenomena are produced by effluvia; (2) these effluvia repel each
other; (3) they are attracted by all other matter. If the word
_fluid_ is substituted for effluvia, these data absolutely agree with
those adopted by Æpinus and Cavendish, forming the basis of the only
satisfactory theory of electricity hitherto proposed.
REFERENCES.--Boulanger, “Traité de la Cause et des phénomènes de
l’électricité,” Paris, 1750, p. 324; _Phil. Trans._ for 1746,
Vol. XLIV. p. 96, and for 1748, Vol. XLV. pp. 195–224, 313; also
the abridgments of John Martyn, Vol. X. part ii. pp. 324, 386,
389, 394; Hutton, Vol. IX. p. 475.
=A.D. 1747.=--Pivati (Johannes Francisco), a Venetian physician,
relates in his “Lettere della elettricita medica,” that if odorous
substances are confined in glass vessels and the latter excited, the
odours and other medical virtues will transpire through the glass,
infect the atmosphere of a conductor, and communicate the virtue they
may possess to all persons in contact therewith; also, that those
substances held in the hands of persons electrified will communicate
their virtue to them so that medicines can thus be made to operate
without being taken in the usual manner.
This appears to have been likewise asserted especially by M. Veratti,
of Bologna, and by M. Bianchi, of Turin; also by Prof. Winckler, of
Leipzig, who satisfied himself of the power of electricity on sulphur,
cinnamon, and on balsam of Peru even at a distance.
By the above-named means of applying the electric fluid Pivati is
reported to have effected cures of ordinary pains and aches, and to
have even relieved of gout the old Bishop Donadoni, of Sebenico, who
had long been a sufferer, and who was at the time seventy-five years
of age. This pretended transudation and its medical effects could not,
however, be verified, even with the directions asked of and given by
Prof. Winckler, when very careful and exhaustive experiments were made,
on the 12th of June, 1751, at the house of Dr. Watson, in presence
of the president and other officers as well as friends of the Royal
Society. Nor could Dr. Bianchini, Professor of Medicine at Venice,
succeed any better. At a later date, Franklin asserted that it was
impossible to combine the virtues of medicines with the electric fluid.
REFERENCES.--Franklin’s Letters, p. 82; _Phil. Trans._ for 1748,
Vol. XLV. pp. 262, 270; for 1750, Vol. XLVI. pp. 348, 368; for
1751, Vol. XLVII. p. 231; for 1753, Vol. XLVIII. pp. 399, 406,
and Vol. X. abridged, pp. 400–403.
=A.D. 1747.=--Louis (Antoine), eminent French surgeon (1723–1792),
publishes “Observations sur l’électricité,” of which the first issue
appeared in 1747 and wherein he indicates the employment of electricity
in medical practice. This he did again in his “Recueils,” upon a more
pretentious scale, six years later, 1753.
REFERENCES.--N. F. J. Eloy, “Dict. de la Médecine,” Mons, 1778,
Vol. III. p. 206; “Gen. Biog. Dict.” of Alex. Chalmers, 1815,
Vol. XX. p. 419; Hœfer, “Nouv. Biog. Gén.,” Vol. XXXI. p. 1033;
Quérard, “La France Littéraire”; “Biog. Univ.,” de Michaud, Vol.
XXV. pp. 319–325.
=A.D. 1747.=--Gralath (Daniel) publishes in the _Dantzig Memoirs_ his
“Geschichte der Electricität.”
He is the first to construct a Leyden phial with a long, narrow neck,
through which is passed an iron wire bearing a tin knob in place of the
iron nail theretofore used; and, with several of these phials joined
together in the form of a battery, he had, during the previous year,
transmitted a shock through a chain of twenty persons. His observations
are recorded in the above-named _Memoirs_ at pp. 175–304 and
506–534, Vol. I.; pp. 355–460, Vol. II.; pp. 492–556, Vol. III.
Gralath’s “Electrische Bibliothek” is in Vols. II. and III.
=A.D. 1747.=--The Swedish mathematician and philosopher, Samuel
Klingenstierna, and his pupil, M. Stroemer, were the first who properly
electrified by the rubber, and their experiments were published in the
Acts of the Royal Academy of Sciences at Stockholm for the year 1747
(see Priestley’s “History of Electricity,” Part I. period viii. s. 3,
wherein he alludes to Wilcke’s “Herrn Franklin’s briefe,” etc., p. 112).
=A.D. 1748.=--Morin (Jean), French physicist, publishes at Chartres
“Nouvelle dissertation sur l’électricité des corps,” etc., in which
he details many of his experiments, and endeavours to give a correct
explanation of all the extraordinary electrical phenomena hitherto
observed. He is also the author of a “Reply to Mr. Nollet upon
Electricity,” published in 1749 at Chartres and at Paris, as well as
of a treatise upon Universal Mechanism, which latter, according to
the _Journal des Savants_, contained more information upon Nature
generally, and expressed in fewer words, than was embraced in any
previous work.
REFERENCES.--“Dict. Univ.,” Vol. XI. p. 568; “Biog. Générale,”
Vol. XXXVI. p. 599.
=A.D. 1749.=--Stukeley (the Rev. William), M.D., is the first who
advanced that earthquakes are probably caused by electricity. This he
did in a paper read before the Royal Society, March 22, 1749, having
reference to the subterranean disturbances noticed in London, February
8 and March 8 of the same year. In this communication, as well as in a
subsequent one read to the same Society, December 6, 1750, bearing upon
a similar disturbance observed throughout England during the previous
month of September, he explains why earthquakes are not the result of
subterraneous winds, fires, vapours, etc.
One of his strongest arguments is that no such vapours could
instantaneously have destroyed thirteen great cities as did the
earthquake which occurred in Asia Minor, A.D. 17, and which is
reckoned to have shaken a cone of earth three hundred miles diameter
in base and two hundred miles in the axis. This quantity of earth, he
says, “all the gunpowder which has ever been made since the invention
of it would not have been able to stir, much less any vapours, which
could be supposed to be generated so far below the surface,” and, he
adds, “if the concussion depended upon a subterraneous eruption the
shock would precede the noise.”
He observes that the earth for months prior to the afore-named
disturbances “must have been in a state of electricity ready for that
particular vibration in which electrification exists”; that all the
vegetation had been “uncommonly forward ... and electricity is well
known to quicken vegetation”; that the aurora borealis had been very
frequent about the same time and had been twice repeated just before
the earthquake, “of such colours as had never been seen before,”
there being, one evening, “a deep red aurora borealis covering the
cope of heaven very terrible to behold”; that the whole year had been
“remarkable for fire-balls, thunder, lightning and coruscations, almost
throughout all England,” all which “are rightly judged to proceed from
the electrical state of the atmosphere”; and, finally, that, a little
before the earthquake, “a large and black cloud suddenly covered the
atmosphere, which probably occasioned the shock by the discharge of
a shower.” He adds that, according to Dr. Childrey, earthquakes are
always preceded by rain and sudden tempests of rain in times of great
drought.