LIGHTNING CONDUCTORS
LONDON: PRINTED BY
SPOTTISWOODE AND CO., NEW-STREET SQUARE
AND PARLIAMENT STREET
[Illustration: MONUMENT TO GENERAL BAIRD ON THE SUMMIT OF TOMACHAISTLE
NEAR CRIEFF PERTHSHIRE. STRUCK BY LIGHTNING, MAY 28, 1878]
LIGHTNING CONDUCTORS
THEIR
HISTORY, NATURE, AND MODE OF APPLICATION
BY
RICHARD ANDERSON, F.C.S. F.G.S.
MEMBER OF THE SOCIETY OF TELEGRAPH ENGINEERS
ASSOC. INST. C. E.
_WITH NUMEROUS ILLUSTRATIONS_
LONDON
E. & F. N. SPON, 46 CHARING CROSS
NEW YORK
446 BROOME STREET
1880
_PREFACE._
The want in England of a good practical work on Lightning Conductors,
accessible to both the professional and non-professional reader, has
long been a subject of remark. That there are English works bearing
more or less on Lightning Protection will be seen at once on reference
to the Bibliography contained in the Appendix, pp. 231–248. But it
will be found these books are either obsolete and out of print, or are
written in a purely popular style that conveys little or no ‘usable’
information whereby may be obtained a trustworthy account of the growth
and application of the LIGHTNING CONDUCTOR.
It is with a view of meeting this need that the present work has been
written. It contains not only a history of the various methods that
have been used to this end, but also a thoroughly practical exposition
of the systems employed by the best authorities in various countries.
To Architects, Clergymen, Municipal Officials, and all those in charge
of large and lofty buildings, it would be impossible to over-estimate
the importance of this subject. Year by year an enormous amount of
property is destroyed merely because the simplest precautions have not
been taken to guard churches and other large buildings from the effects
of thunder storms.
The Author of this work can at all events claim a large practical
acquaintance with its subject. He feels convinced that those concerned
in the preservation of buildings, whether they be houses, churches, or
public offices, need only to learn the simple methods that can be used
to render the action of lightning innocuous, in order to adopt them.
R. A.
NEW MALDEN, SURREY:
_October 1879_.
_CONTENTS._
CHAPTER PAGE
LIST OF BOOKS REFERRED TO, OR CONSULTED, RELATING TO
LIGHTNING CONDUCTORS xi
I. ELECTRICITY AND LIGHTNING 1
II. DISCOVERY OF THE LIGHTNING CONDUCTOR 17
III. EARLY EXPERIMENTS WITH LIGHTNING CONDUCTORS 25
IV. GRADUAL SPREAD OF LIGHTNING CONDUCTORS IN EUROPE 34
V. METALS AS CONDUCTORS OF ELECTRICITY 49
VI. CHARACTER OF LIGHTNING AND OF THUNDERSTORMS 62
VII. INQUIRIES INTO LIGHTNING PROTECTION 73
VIII. SIR WILLIAM SNOW HARRIS 85
IX. THE BEST MATERIAL FOR CONDUCTORS 100
X. HÔTEL DE VILLE, BRUSSELS, AND WESTMINSTER PALACE 111
XI. WEATHERCOCKS 121
XII. LIGHTNING PROTECTION IN FRANCE AND AMERICA 125
XIII. LIGHTNING PROTECTION IN ENGLAND 140
XIV. ACCIDENTS AND FATALITIES FROM LIGHTNING 169
XV. THE EARTH CONNECTION 198
XVI. INSPECTION OF LIGHTNING CONDUCTORS 218
APPENDIX 231
INDEX 249
_LIST OF BOOKS_
REFERRED TO, OR CONSULTED, RELATING TO THE HISTORY, NATURE, AND MODE OF
APPLICATION OF
LIGHTNING CONDUCTORS.
ACHARD (Fr. K.) Kurze Anleitung ländliche Gebäude vor
Gewitterchäden sicher zu stellen. 8vo. Berlin, 1798.
ARAGO (François). Meteorological Essays. Translated by Colonel
Sabine; with an Introduction by Baron von Humboldt. 8vo.
London, 1855.
BARBERET (J.) Dissertation sur le Rapport qui existe entre les
Phénomènes de Tonnerre et ceux de l’Electricité. 2 vols. 4to.
Bordeaux, 1750.
BEAUFORT (Dr. Antonin de). Notice sur les Paratonnerres. 8vo.
Châteauroux, 1875.
BECCARIA (C. B.) Lettere dell’ Elettricismo. 4to. Bologna, 1758.
BECCARIA (Giambatista). A Treatise upon Artificial Electricity.
Translated from the Italian. 8vo. London, 1776.
BECQUEREL (Antoine C.) Traité de l’Electricité et du Magnétisme. 7
vols. 8vo. Paris, 1834–40.
BERGMAN (T.) Tal on möjeligheten at förexomma askans skadeliga
werkningar. 4to. Stockholm, 1764.
BIGOT (P.) Anweisung zur Anlegung, Construction und Veranschlagung
der Blitzableiter. 8vo. Glogau, 1834.
BODDE (M.) Grundzüge zur Theorie der Blitzableiter. 8vo. Münster,
1804.
BOECKMANN (N.) Ueber die Blitzableiter. 8vo. Karlsruhe, 1791.
BREITINGER (D.) Instruction über Blitzableiter. 4to. Zürich, 1830.
BUCHNER (Dr. Otto). Die Konstruction und Anlegung der
Blitzableiter, mit einem Atlas. 2nd edition, 8vo. Weimar, 1876.
CALLAUD (A.) Traité des Paratonnerres. 8vo. Paris, 1874.
CAVALLO (Tiberius). A Complete Treatise on Electricity. 2 vols.
8vo. London, 1786.
DALIBARD (M.) Histoire abrégée de l’Electricité. 2 vols. 8vo.
Paris, 1766.
DAVY (Sir Humphrey). Elements of Chemical Philosophy. 8vo. London,
1810.
DEMPP (K. W.) Vollständiger Unterricht in der Technik der
Blitzableitersetzung. 8vo. München, 1842.
EBERHARD (Dr.) Vorschläge zur bequemeren und zicherern Anlegung der
Pulvermagazine. 8vo. Halle, 1771.
EISENLOHR (Dr. W.) Anleitung zur Ausführung und Visitation der
Blitzableiter. 8vo. Karlsruhe, 1848.
EITELWEIN (J. A.) Kurze Anleitung auf welche Art Blitzableiter an
den Gebäuden anzulegen sind. 8vo. Berlin, 1802.
FAIT (E. M.) Observations concerning Thunder and Electricity. 8vo.
Edinburgh, 1794.
FERGUSON (James). An Introduction to Electricity. 3rd edition, 8vo.
London, 1778.
FIGUIER (Louis). Les Merveilles de la Science. 4to. Paris, 1867.
FONVIELLE (Wilfrid de). Eclairs et Tonnerres. 8vo. Paris, 1869.
FONVIELLE (Wilfrid de). De l’Utilité des Paratonnerres. 8vo. Paris,
1874.
FRANKLIN (Benjamin). Experiments and Observations in Electricity,
made at Philadelphia, in America. 8vo. London, 1751.
FRANKLIN (Benjamin). Complete Works in Philosophy, Politics, and
Morals. 3 vols. 8vo. London, 1806.
FRANKLIN (William Temple). Memoirs of the Life and Writings of
Benjamin Franklin. 4to. London, 1818.
GAY-LUSSAC (F.) et POUILLET (Claude). Introduction sur les
Paratonnerres, adoptée par l’Académie des Sciences. 8vo. Paris,
1874.
GRENET (E.) Construction de Paratonnerres. 8vo. Paris, 1873.
GROSS (J. F.) Grundsätze der Blitzableitungskunst. 8vo. Leipzig,
1796.
GUERICKE (Otto von). Experimenta nova Magdeburgica. Folio.
Amsterdam, 1672.
GÜTLE (J. K.) Neue Erfahrungen über die beste Art Blitzableiter
anzulegen. 8vo. Nürnberg, 1812.
HARRIS (William Snow) On the Nature of Thunderstorms, and the Means
of Protecting Buildings and Shipping against Lightning. 8vo.
London, 1843.
HARRIS (Sir William Snow). A Treatise on Frictional Electricity.
Edited by Charles Tomlinson. 8vo. London, 1867.
HELFENZRIEDER (J.) Verbesserung der Blitzableiter. 8vo. Eichstädt,
1783.
HEMMER (J. J.) Kurzer Begriff und Nutzen der Blitzableiter. 8vo.
Mannheim, 1783.
HEMMER (J. J.) Anleitung Wasserableiter an allen Gattungen vor
Gebäuden auf die sicherste Art anzulegen. 8vo. Frankfurt, 1786.
HENLEY (William). Experiments concerning the Different Efficacy
of Pointed and Blunt Rocks in securing Buildings against the
Stroke of Lightning. 8vo. London, 1774.
HOLTZ (Dr. W.) Ueber die Theorie, die Anlage und die Prüfung der
Blitzableiter. 8vo. Greifswald, 1878.
IMHOF (M. von). Theoretisch-practische Anweisung zur Anlegung
zweckmässiger Blitzableiter. 8vo. München, 1816.
INGENHOUSZ (Dr. Johan). New Experiments and Observations concerning
Various Subjects. 8vo. London, 1779.
KLEIN (Hermann J.) Das Gewitter und die dasselbe begleitenden
Erscheinungen. 8vo. Graz, 1871.
KUHN (Carl). Handbuch der angewandten Elektricitätslehre. Part I.
Ueber Blitzableiter. 8vo. Leipzig, 1866.
LANDRIANI (M.) Dell’ Utilità di Conduttori elettrici. 4to. Milano,
1785.
LAPOSTOLLE (M.) Traité des Parafoudres et des Paragrêles. 8vo.
Amiens, 1820.
LENZ (Heinrich F. E.) Handbuch der Physik. 2 vols., 8vo.
Petersburg, 1864.
LICHTENBERG (G. Ch.) Neueste Geschichte der Blitzableiter. 8vo.
Leipzig, 1803.
LUTZ (F.) Unterricht vom Blitze und Wetterableitern. 8vo. Nürnberg,
1783.
MAFFEI (F. S.) Delle Formazione dei Fulmini. 4to. Verona, 1747.
MAHON (Lord). Principles of Electricity. 4to. Elmsly, 1780.
MARUM (M. van). Verhandeling over hat Electrizeeren. 8vo.
Groningen, 1776.
MELSENS (M.) Notes sur les Paratonnerres, in ‘Bulletins de
l’Académie Royale de Belgique.’ 8vo. Bruxelles, 1874–78.
MELSENS (M.) Des Paratonnerres. 4to. Bruxelles, 1877.
MEURER (Heinrich). Abhandlung von dem Blitze und den
Verwahrungsmitteln gegen denselben. 4to. Trier, 1791.
MURRAY (N.) Treatise on Atmospheric Electricity, including
Observations on Lightning Rods. 8vo. London, 1828.
NEWALL (R. S.) Lightning Conductors: their use as protectors of
buildings, and how to apply them. 8vo. London, 1876.
NOAD (Henry M.) Lectures on Electricity. 8vo. London, 1849.
NOAD (Henry M.) A Manual of Electricity. 8vo. London, 1855.
NOLLET (Abbé J. A.) Leçons de Physique expérimentale. 6 vols. 12mo.
Paris, 1743.
NOLLET (Abbé J. A.) Recherches sur les Causes particulières des
Phénomènes électriques. 8vo. Paris, 1749.
OHM (Georg Simon). Bestimmung des Gesetzes nach welchem die Metalle
die Contact-Electricität leiten. 8vo. Nürnberg, 1826.
PARTON (James). Life and Times of Benjamin Franklin. 2 vols. 8vo.
New York, 1864.
PHIN (John). Plain Directions for the Construction of Lightning
Rods. 8vo. New York, 1873.
PLIENINGER (Dr. P.) Ueber die Blitzableiter. 8vo. Stuttgart, 1835.
PONCELET (Abbé M.) La Nature dans la Formation du Tonnerre. 8vo.
Paris, 1766.
POUILLET (Claude S. M.) Eléments de Physique expérimentale et de
Météorologie. 7th edition, 2 vols. 8vo. Paris, 1856.
PRAIBSCH (Christian). Ueber Blitzableiter, deren Nutzbarkeit und
Anlegung. 8vo. Zittau und Leipzig, 1830.
PREECE (W. H.) On Lightning and Lightning Conductors, in ‘Journal
of the Society of Telegraph Engineers.’ 8vo. London, 1873.
PRIESTLEY (Dr. Joseph). The History and Present State of
Electricity. 2 vols. 8vo. London, 1775.
REIMARUS (J. A. H.) Vom Blitze. 8vo. Hamburg, 1778.
REIMARUS (J. A. H.) Ausführliche Vorschriften zur Blitz-Ableitung
an allerlei Gebäuden. 8vo. Hamburg, 1794.
ROBERTS (M.) On Lightning Conductors, particularly as applied to
Vessels. 2 vols. 8vo. London, 1837.
ROWELL (G. A.) An Essay on the Cause of Rain and its Allied
Phenomena. 8vo. Oxford, 1859.
SAUSSURE (H. B. de). Manifeste, en exposition abrégée, de l’Utilité
des Conducteurs électriques. 8vo. Genève, 1771.
SIGAUD DE LA FOND (M.) Précis historique et expérimental des
Phénomènes électriques. 2nd edition, 8vo. Paris, 1785.
SINGER (George John). Elements of Electricity. 8vo. London, 1814.
SPANG (Henry W.) A Practical Treatise on Lightning Protection. 8vo.
Philadelphia, 1877.
SPARKS (Jared). The Works of Benjamin Franklin; with Notes and a
Life of the Author. 10 vols. 8vo. Boston, 1840.
SPRAGUE (John F.) Electricity: its Theory, Sources, and
Applications. 8vo. London, 1875.
STRICKER (Dr. Wilhelm). Der Blitz und seine Wirkungen. 8vo. Berlin,
1872.
STURGEON (William). Lectures on Electricity. 8vo. London, 1842.
TAVERNIER (A. de). Blitzableiter, genannt Anti-Jupiter. 8vo.
Leipzig, 1833.
TINAN (Barbier de). Mémoires sur les Conducteurs pour préserver les
Edifices de la Foudre. 8vo. Strasbourg, 1779.
TOALDO (Giuseppe). Della Maniera di defendere gli Edifizii dal
Fulmine. 8vo. Firenze, 1770.
TOALDO (Giuseppe). Dei Conduttori per preservare gli Edifizii da
Fulmine. 4to. Venezia, 1778.
TOMLINSON (Charles). The Thunderstorm. 8vo. London, 1859.
TYNDALL (John). Notes on Electrical Phenomena. New edition, 8vo.
London, 1876.
VERATTI (J.) Dissertatione de Electricitati cœlesti. 8vo. Bologna,
1755.
WEBER (F. A.) Abhandlung von Gewitter und Gewitterableiter. 8vo.
Zürich, 1792.
WHARTON (W. L.) The Effect of a Lightning Stroke. 8vo. London, 1841.
WILSON (Robert). Boiler and Factory Chimneys; with a chapter on
Lightning Conductors. 8vo. London, 1877.
WINCKLER (Prof. J. H.) Gedanken von den Eigenschaften, Wirkungen
und Ursachen der Elektricität. 8vo. Leipzig, 1744.
YELIN (J. C. von). Ueber die Blitzableiter aus
Messingdrahtstricken. 8vo. München, 1824.
LIGHTNING CONDUCTORS:
THEIR
HISTORY, NATURE, AND MODE OF APPLICATION.
CHAPTER I.
ELECTRICITY AND LIGHTNING.
‘First let me talk with this philosopher: What is the cause of
thunder?’ asks Shakspeare in ‘King Lear’ but without giving a reply.
The ‘philosopher’ of Shakspeare’s days had no answer to make; nor
had any others long after. From the dawn of history till within
comparatively modern times, thunder and lightning were mysteries to the
human mind; nor did there exist so much as a surmise that there might
be any connection between them and the equally mysterious agent called
electricity. The latter force indeed revealed itself early to attentive
observers, though in forms very different from those known at the
present time. The Greeks found out that amber, or ‘electron,’ attracted
certain other bodies under friction, and named the force after it; and
the Romans were aware that the shocks discharged by the torpedo fish
were of electrical nature, and they used them for the cure of rheumatic
complaints in the reign of the Emperor Tiberius. Both Greeks and Romans
also observed the sparks emitted, under certain circumstances, from
clothing and from the fur of animals. But this represented the total
sum of knowledge about electricity for ages and ages.
It was not until the year 1600 that Dr. William Gilbert, physician
to Queen Elizabeth, made a great step forward by showing in his
celebrated work, ‘De magnete, magneticisque corporibus, et de magno
magnete tellure, physiologia nova,’ that the two classes of phenomena,
the magnetic and the electric, are emanations of a single fundamental
force pervading all nature. Dr. Gilbert further discovered that many
other substances besides amber possess the electric power, and that
this power is easily excited when the air is dry and cool, and with
difficulty when it is moist and warm. These discoveries caused great
commotion in the European learned world, yet produced no further result
for another half a century. In 1650, Otto von Guericke, burgomaster
of Magdeburg, the inventor of the air-pump, who had studied with
deep interest Dr. Gilbert’s book, succeeded in constructing a little
electrical machine, composed mainly of a ball of sulphur mounted
on a revolving axis. By the aid of this instrument, very rude in
construction, he produced powerful sparks and flashes of electric
light, and it helped him likewise to discover, first, that bodies
excited by friction communicate their electricity to other bodies
by mere contact, and, secondly, that there resides in electrified
substances the power of repulsion as well as that of attraction.
Those who followed in the wake of the ingenious burgomaster of
Magdeburg for the next ninety or hundred years, till towards the middle
of the eighteenth century, did very little towards adding to the
already acquired knowledge of electricity. Sir Isaac Newton constructed
an electrical machine of glass, very superior to that of Otto von
Guericke, with which he made some amusing experiments; but, strangely
enough, drew no conclusions from them, treating the mighty force under
his eyes as only a plaything. This was all the more singular as a
contemporary of the great philosopher, Francis Hauksbee, like him a
Fellow of the Royal Society, called attention, in a volume entitled
‘Physico-mechanical Experiments,’ published in 1709, to the great
similarity between the electric flash and lightning, hinting that the
two might possibly be offspring of the same mysterious force. Dr. Wall,
in 1708, said that the light and crackling of rubbed amber seemed in
some degree to represent thunder and lightning. Another member of the
Royal Society, Stephen Gray--the first man in England who made the
study of electricity the devotion of his life, but of whose career very
little is known beyond the fact that he was very poor, and a pensioner
of the Charterhouse--added numberless experiments to those previously
made, and was bold enough to declare, in 1720, six years before Sir
Isaac Newton’s death, that ‘electricity seems to be of the same nature
with thunder and lightning--if we may compare great things with small.’
For this audacity in ‘comparing things’ he was sharply taken to task by
all the scientific men of the age, and, as deserved, set down as a man
out of his senses.
Nothing more was done for the next twenty-five years to enlarge the
knowledge of the phenomena of electricity. It stood, in fact, on a
footing not very far advanced from what it had been two thousand
years before. The achievements mainly consisted in a great number
of entertaining experiments performed for the delectation of great
and little children. Various machines had been made for exciting
electricity, but they served only, or at least chiefly, for amusement,
allowing ladies to fire off a cannon by a touch of their delicate hand,
and bringing ladies and gentlemen together to behold the wonderful
spectacle of an infant’s hair being made to stand on end, the little
creature having been placed upon cakes of resin, and fastened to the
ceiling by silken cords. The whole was little more than a repetition,
on a greater scale and with improved means, of the ancient Greek
experiment of rubbing a piece of amber on the sleeve of a philosopher’s
coat.
The first great step towards a practical insight into the nature and
phenomena of electricity, hitherto a mere plaything, was made in
the year 1745 in the ancient Dutch city and university of Leyden.
Two professors of the high school, John Nicholas Allamand, a member
of the Royal Society of London, and Peter Van Musschenbroek, author
of a treatise entitled ‘Introductio ad philosophiam naturalem,’ had
been trying, like many other scientific men of the time, electrical
experiments, when the thought occurred to them that the real reason
why all the work of the same kind had as yet produced such slight
results was that the electrical force was absolutely unstable. It
slipped, so to speak, through their hands, before they could look at
it; it vanished ‘like a dream, leaving no substance behind.’ One body,
they knew, had the power of electrifying another, but only to let
the mysterious force pass on, like a current of water running down a
cataract. Could they but ‘bottle up’ electricity, what a grand gain
would this be to science! So thought the two professors of Leyden
university; and thought justly. They went on experimenting, with this
end in view, till at last so-called ‘accident,’ the mother of millions
of human inventions and discoveries, threw a brilliant light on the
dark road along which they were groping their way.
One day Professor Allamand and Van Musschenbroek, together with a pupil
named Cuneus--a sort of Wagner, it would seem, sitting at the feet
of Dr. Faust--were trying the effects of electricity on a small iron
cannon, suspended by silk threads, and connected by a wire with a glass
bottle half full of water, when whey were startled by an extraordinary
incident. Curious, like all students of occult sciences, young Cuneus
took it into his head to see what would happen if he held the prime
conductor of the electrical machine in one hand and the electrified
bottle of water in the other. Something wonderful happened, indeed,
causing profound amazement and terror to the three persons witnessing
it, most of all to the immediate experimenter, who sank down on the
floor, half dead with fright. Master Cuneus had received an electric
shock. It was the first electric shock ever administered by artificial
means to any human being.
Such was the origin of the long-famous ‘Leyden jar,’ or, as it was
originally called, ‘Leyden phial.’ The whole of the scientific world
of Europe was as much startled by the discovery that electricity
could be imprisoned, like Ariel in an oak-tree, as the two Leyden
professors and their pupil had been, and a perfect fury set in for more
experiments. A professor of the University of Leipzig, in Germany, Dr.
Winckler, started the excitement by submitting his body to frequent
powerful shocks, opening up, besides, a scientific discussion in which
he came forth as the champion of the proposition that the discovery
of the ‘Leyden phial’ was due, not to the professors in the Dutch
university, but to a German ecclesiastic, Ewald George von Kleist,
who made the experiments of Messrs. Allamand and Van Musschenbroek a
year before them. His own sensations in submitting to the force of
electric shocks, Professor Winckler described, doubtless with some
exaggeration, as being convulsed from head to toe, and the prey of
violent agitations, which threw his arms about, and made the blood rush
from his nose. Dr. Winckler did not venture upon many experiments; but
his spouse, undismayed by the arm-shaking and nose-bleeding of her
lord, and having the combined curiosity of a woman and a professor’s
wife, continued upon her own person the electric shocks. However,
she did not take many, nor did science gain by the sacrifice. When a
few graspings of the ‘Leyden phial’ had deprived her of the power to
walk, and, what was worse, to speak, she followed the example of her
bleeding husband, and took ‘cooling medicines.’ All these wonderful
facts were made widely known at the time, and created the most profound
interest. Professor Musschenbroek, of Leyden, added not a little to the
prevailing excitement by writing to his friend René Antoine de Réaumur,
inventor of the thermometer named after him, a long letter, given at
once to the public, in which he dwelt upon the terrible effects of the
mysterious agency which he had helped to call into being, and wound
up by declaring that he had become terrified by his own foster-child,
and that he would not submit to another electric shock ‘for the whole
kingdom of France.’
Experiments in electricity now became the prevailing mania. Louis XV.
of France set the fashion among crowned heads of having his soldiers
electrified, to see what benefit he, or they, would derive from it. On
the instigation of Abbé Nollet, considered a man of high scientific
attainments, and who made several important discoveries in electricity,
the King submitted, in his own presence, 180 of the tallest men of his
life-guards, fastened hand to hand by iron wires, to repeated charges
from a connected group of Leyden jars. The big fellows were not visibly
influenced by the electric shocks, experiencing not so much as the
historical nose-bleeding of Professor Winckler of Leipzig, still less
the dumbness of his worthy spouse. On the contrary, the wire-bound
royal guards, conscious of but very slight sensations from the electric
shocks, and feeling somewhat indignant at this, and of being made
scientific tools without at least getting a strong bump on the head,
spoke out strongly, declaring the whole matter to be an imposture.
Having failed to electrify his soldiers, Louis XV. tried his monks.
It struck his Most Christian Majesty that perhaps the human creatures
who had the honour of fighting for him were endowed by nature with
rather tough hides, and that the case might be different in regard
to the softer beings upon whom devolved the task of praying for him.
Accordingly, the King issued orders that all the monks of the grand
convent of the Carthusians at Paris, over 700 in number, should be
electrified by the same connected group of Leyden jars which had
been tried upon the company of life-guards. The result was entirely
different, and most gratifying to the King. The shock had no sooner
been given when the whole file of monks gave an instantaneous jump,
uttering a howl at the same time. There were some eye-witnesses of
the affair who asserted that the Carthusians jumped and howled even
before the shock had been given, on seeing some one approach the Leyden
jar; but this was officially denied. King Louis XV. was so delighted
with this result of his scientific investigations, that he proposed
to submit all the monks of all the monasteries of France successively
to the process of being electrified, so that it might be accurately
ascertained upon what religious orders and communities it took the
greatest effect. His Majesty likewise was pleased to suggest, that,
after all the monks had been electrified, the nuns might be tried in
their turn. But the proposal was vetoed at Rome. There came definite
orders from the Supreme Pontiff forbidding the contact of any more
persons in the service of the holy Catholic Church with the sinful
electric wire; and the Carthusians of Paris remained the last monks,
as they had been the first, brought to jump and howl at the touch of a
Leyden jar.
From France and the continent of Europe the mania for electrical
experiments spread into England. But here it was taken up in a
thoroughly practical spirit, worthy of the genius of the nation.
Instead of aiming merely at the production of wonderful phenomena,
made to create astonishment, a number of scientific gentlemen formed
themselves into a body for the express purpose of seeking to ascertain
the nature, effects, and conditions of the mysterious agent which had
obtained the name of electricity. At the head of this body of inquirers
was Dr. William Watson, a member of the Royal Society, indefatigable
in the pursuit of science, and with him worked Martin Folkes, then
president of the Society, Lord Charles Cavendish, Dr. Bevis, and other
distinguished men. They set themselves, first of all, to ascertain in
what manner electricity was communicated through the solid earth, as
well as through fluid bodies; and, secondly, to enter upon experiments
showing the amount of speed at which the force travelled. With the
first object before them, they made some curious trials in the month
of July 1747, which attracted all London. They hung a wire over the
Thames, close to Westminster Bridge, attaching the one end to a Leyden
jar, and giving the other to a man who held it in the left hand, while
he grasped with the right an iron rod, standing in the river. Facing
the latter, on the opposite side of the Thames, not far from the
operators with the ‘jar,’ was stationed another person, also grasping
an iron staff planted in the river. After the charge had been given,
it was found that the electricity, after travelling by the wire over
the river, had come back by the water, the person holding the iron
staff on the starting side not only experiencing a shock himself, but
several individuals touching him. Not content with this experiment,
showing the transmission of electricity, Dr. Watson and his friends
made another, on a larger scale, a week afterwards, on the New River,
at Stoke Newington, London. They spanned, by chains and wires, a
circuit embracing 800 feet by land and 2,000 by water, with the result
of finding that the water transmitted the electric force by itself, if
merely an iron staff was placed in it. But they also discovered at the
same time that moist land would carry the force, equally with water.
To ascertain the latter fact more distinctly, the investigators made
a third experiment at Highbury Barn, Islington, setting up some miles
of wire, separated partly by land and partly by water. The conduit
of the electric force throughout the whole distance was found to be
uninterrupted, which led Dr. Watson to proclaim his conviction that the
agent was far more abundant throughout nature than had been formerly
believed.
In order to ascertain the speed at which the electric force traversed
space, Dr. Watson and his friends next entered upon a series of
experiments at Shooter’s Hill, near London. They sent an electric
discharge a distance of four miles, observers being stationed at each
end, and a gun fired at the touch of the Leyden jar, when it was shown
conclusively that the movement of the electric force was instantaneous.
This was an important step in advance, in overthrowing all formerly
established conclusions as to the agency being produced by a succession
of waves, like sound, and as such, moving slowly through space.
The field for electrical experiments was now becoming gradually
more extensive, and a few more practical tests of Mr. Watson and his
coadjutors led the way to the greatest knowledge of the all-pervading
force that had yet been achieved, in the clear apprehension that
lightning was but a manifestation of electricity. The new experiments
were chiefly made with the so-called electrical tube, a glass rod, from
two and a half to three feet in length and about an inch in diameter.
It had been known for some time that the tube, when gently warmed, so
as to be perfectly dry, and rubbed with a silk handkerchief, exhibited
strong symptoms of electricity, to the extent of throwing off luminous
sparks, which obtained the name of ‘electric fire.’ Dr. Watson found,
to his surprise, that this electric fire was not general and always
obtainable, but conditional upon circumstances. Having rubbed a glass
tube while he was insulated by standing upon a cake of wax, he found
that no electricity could be drawn from him by another person who
touched any part of his body, but that the same person could obtain
sparks from the tube by putting his hand near it. Dr. Watson likewise
observed, in the same train of experiments, that if an electrical
machine, together with the person turning the handle, were suspended
by silk, electric fire was not apparent until he touched the floor
with one foot, when the fire appeared upon the conductor. Having made
a great number of trials of a like nature, Dr. Watson made known the
important conclusion derived from them, namely, that glass tubes and
all similar ‘electrifiers’ did not contain within themselves the subtle
agent known as electricity, but formed only its temporary place of
rest, as a sponge would that of water. Dr. Watson was near proclaiming
the fact that electricity resides everywhere throughout the universe;
but for a moment he only touched the fringe of it. The discovery of
this grand truth was left to later investigators.
One curious result of the experiments made by Dr. Watson and his
friends, and which they themselves probably did not expect, was the
breaking out of a sort of public frenzy for making like trials, but
after the most childish fashion. Everybody who had, or thought he had,
the least tincture of science in him, procured a long glass tube,
and went on rubbing it assiduously with his handkerchief, sitting in
dark rooms and cellars, so as to be better able to watch the first
appearance of the ‘electric fire.’ Ladies and gentlemen alike went on
rubbing, with desperate energy, as if the fate of the world depended on
their exertions. They sold ‘electrical tubes’ in pastry shops; every
draper praised his own handkerchiefs as the best for rubbing; and
lecturers upon electricity went about through the length and breadth
of the land, with glass rods in their hands, delivering wonderful
harangues, and trying to explain to gaping multitudes the mysteries of
nature as regards electricity. The lecturers even crossed the Atlantic
to America, visiting the chief towns, and preaching to large assemblies
in places--
Where blind and naked ignorance
Delivers brawling judgments, unabashed
On all things, all day long.
If it was a ludicrous spectacle to see these wandering lecturers, with
their glass tubes and pocket-handkerchiefs, the movement nevertheless
produced, apparently quite by accident, a striking result. It occurred
through one of the peripatetic preachers of electric revelation
coming face to face with Benjamin Franklin, a printer established
at Philadelphia, when on a visit to his native town of Boston,
Massachusetts, North America.
There are, in the records of scientific discovery, few figures so
interesting, because so full of marked individualism, as that of
Benjamin Franklin. He was not a man of genius, in the accepted sense
of the word; nor was he even a man of high talents. But he was
nevertheless a decidedly great man, his greatness consisting in the
largest development of that undefined faculty known as common sense.
Benjamin Franklin was the very ideal of a ‘practical’ man, that is,
a man valuing thoughts only as leading to actions, and new ideas
only as the road to visible results. The success of his career in
life was but an illustration of his thoroughly practical character.
Born at Boston in January 1706, the son of a tallow-chandler and
soap-boiler, he was destined by his parents to follow the same trade,
but not relishing the melting pots, he got apprenticed to an elder
brother, a printer at Boston. Harsh treatment drove him away from
this place before the terms of his apprenticeship were over, and with
scarcely a penny in his pocket, and the experience of only seventeen
years in his brain, he made his way to Philadelphia. A year after,
when eighteen years of age, he was induced to sail for England, and
was fortunate enough to find employment as a compositor in a printing
office in London, but so poor as to be compelled to take a lodging
for eighteen-pence a week. However, his self-reliance never deserted
him; he managed to go unscathed through all the perils of poverty and
friendlessness in a great city, and after a few years went back to
Philadelphia, with a small stock of money and a wealth of experience.
He now set up as a master printer, and gradually, though by very slow
degrees and ceaseless toil, devoted to multifarious objects, rose into
prosperity. For upwards of twenty years, from 1728 to 1748, he was the
most energetic and active man of business in Philadelphia. He was not
only a printer, but an author, an editor of newspapers, a compiler of
almanacks, a publisher, a bookseller, a bookbinder, and a stationer.
He made lamp-black and ink; he dealt in rags; he sold soap and geese
feathers; also, as he frequently made known to his fellow-townsmen
in printed notices, he had always in stock ‘very good sack at six
shillings a gallon.’ To dispose of the numerous articles in his store
he invented the art of advertising, unknown before him at Philadelphia.
All the inquiring minds of the ‘Quaker City’ assembled regularly in the
shop of Benjamin Franklin, ‘the new printing office near the market,’
which came to form the centre of intelligence, and the source from
which all public movements went forth.
The reward for all this activity was that at the end of twenty years
Benjamin Franklin had accumulated a handsome fortune, his average
income amounting to over two thousand pounds sterling a year: then
considered a very large sum, and of probably three times the purchase
value it would possess at the present day. With increasing wealth,
the active printer, happy in all his family relations, thought
himself justified to seek a little occasional leisure, which he found
chiefly in visits to Boston, his native town. It was on one of these
visits, made in the summer of 1746, that he went with a friend to
a lecture-hall, scarcely knowing what was to be the intellectual
entertainment prepared for him. It proved a discourse, with
illustrative experiments, upon electricity, by a Dr. Spence, duly armed
with a three-feet glass rod and silk pocket-handkerchief. Benjamin
Franklin was not merely interested: he was startled. It was to him,
as he afterwards declared to one of his friends, the opening of a new
world.
Perhaps the subject which attracted so suddenly the attention of
Benjamin Franklin might have escaped it again, in the pursuit of his
many vocations, but for another accidental circumstance. It so happened
that, immediately after his return to Philadelphia, there came a parcel
of books from England, accompanied by a present in the shape of an
electrical tube. The sender of it was the London agent of the Library
Company of Philadelphia, Mr. Peter Collinson, a member of the Royal
Society, and as such sharing the general interest in the electrical
experiments of Dr. Watson. The tube, which was accompanied with full
directions for its use, was no sooner unpacked, than Franklin seized
it eagerly and began experimenting, at the same time inspiring the
most sanguine of his friends to follow his example. Glass tubes, made
similar to the one sent from London, were soon procured from a local
manufacturer, and then began a general rubbing. ‘I never before,’
Franklin wrote, early in 1747, ‘was engaged in any study that so
totally engrossed my attention and my time as this has lately done; for
what with making experiments when I can be alone, and repeating them to
my friends and acquaintances, who, from the novelty of the thing, come
continually in crowds to see them, I have, during some months past,
had little leisure for anything else.’ To the greater number of those
friends and acquaintances who came flocking in crowds to the shop of
the Philadelphia printer, the electric tube was, probably, only looked
upon as a new toy; but it was vastly different as regarded himself. His
keen practical eye seemed to discern at once that the manifestations of
the mysterious force on which he was experimenting contained the germ
of something that might be utilised by men, or brought into obedience
to the human will.
It is not very clear from the published correspondence of Franklin what
his earliest views on the subject were, but there are many indications
that he conceived for a while that the ‘electric fire’ might be
employed in arts and manufactures. In his usual humorous style he spoke
of these utilitarian aims of his in a letter to Mr. Peter Collinson,
written in the early summer of 1747: ‘Chagrined a little that we
have not been able to produce hitherto anything in the way of use to
mankind,’ he wrote, ‘and the hot weather coming on, when electrical
experiments are not so agreeable, it is proposed to put an end to them,
for this season, in a party of pleasure on the banks of the Schuylkill.
Spirits at this party are to be fired by a spark sent from side to
side through the river, without any other conductor than the water:
an experiment which we some time since performed, to the amazement of
many. Then a turkey is to be killed for our dinner by the electrical
shock, and roasted by the electrical jack, before a fire kindled by the
electrified bottle, when the healths of all the famous electricians in
England, Holland, France, and Germany are to be drunk in electrified
bumpers, under the discharge of guns from the electrical battery.’
The longer he experimented, the more fascinated grew Benjamin Franklin
with his study of the phenomena of electricity. In order to be able to
devote himself completely to his darling science, he sold his printing
and publishing business in the year 1748, and went to live in a suburb
of Philadelphia, not far from the banks of the Delaware. At the same
time he purchased a complete set of electrical apparatus, the best that
had yet been manufactured, which had been brought over from Europe by
the same Dr. Spence who had given him his first ideas about electricity
at Boston. With these more perfect means he now continued his
investigations, arriving before long at results that formed an epoch in
the history of electricity.
The results achieved were wholly of a practical kind. With that strong
common sense which formed the most marked feature of his character,
Benjamin Franklin, at a very early period of his experiments, came
to the conclusion that of the actual _nature_ of electricity we know
nothing, and, in all probability, never can know anything, with our
finite senses. But, never losing sight of this starting point, he
treated electricity as astronomers do the movement of the heavenly
bodies. Of the incomprehensible forces that keep countless worlds in
their courses through measureless space, astronomers know no more than
the most ignorant of mankind; still they are able to arrive at very
accurate calculations concerning the directions followed by stars and
planets, and the amount of time consumed in their wanderings through
the inconceivable universe. To such astronomical endeavours Franklin
limited all his researches, and it was precisely because he so limited
them that he achieved greater successes than any other investigator of
the phenomena of electricity.
Together with many smaller matters, Benjamin Franklin added three great
discoveries to the knowledge of electricity. The first was that the
electric fluid--so called for want of a better word to express the
action of the mysterious force--will run its course more easily and
quickly through sharply pointed metals than in any other way. This had
never before been demonstrated, nor, probably, been ascertained. The
second great discovery of Franklin was that of positive and negative
electricity, or, as he called it for some time, _plus_ and _minus_,
the latter names being really the most descriptive. Of the actual
existence of these two divisions of the great and marvellous agency,
now attracting and now repelling each other, much was known previous
to Franklin, but he was the first to make them clearly understood,
and to bring their effects within reach of calculation. To these two
discoveries Benjamin Franklin added a third, the greatest of all. He
established the identity between the electric force and lightning,
and upon it based one of the noblest inventions of all ages, that of
the lightning conductor. And perhaps there never was any invention
acknowledged more deeply by mankind. The French Academy expressed it
when, on Franklin’s entrance, all the members rose, and the President
exclaimed ‘_Eripuit cœlo fulmen_.’
The identity of the electric force and lightning, vaguely surmised
by previous inquirers, and expressed at times in hints, was not only
firmly asserted by Benjamin Franklin, but at a comparatively early part
of his investigations proved by him in experiments. His broad practical
way of looking at facts succeeded in grasping a truth which all the
learned men before him, who had busied themselves with electrical
experiments, had not been able to lay hold of, simply because they lost
themselves in philosophical abstractions. The professors sought the
unattainable, and he confined himself strictly to what he considered
within reach, and it was thus he gained his end.
The thoroughly matter-of-fact way in which Franklin went to work
is strikingly exhibited in his own description as to how he came
to the conclusion of the oneness of lightning and electricity. In
reply to a friend and correspondent, living in South Carolina, who
had asked him how he came to such an ‘out-of-the-way idea’ as that
of the majestic fire from the cloud-capped firmament being exactly
the same with the puny gleam from a stick of glass, rubbed with the
sleeve of an old coat, Franklin wrote a highly characteristic letter.
‘I cannot answer your question better,’ he told his friend, ‘than
by giving you an extract from the minutes I used to keep of the
experiments I made. By this extract you will see that the thought was
not so much an out-of-the-way one but that it might have occurred to
any electrician. The extract, dated November 7, 1749--a date worth
remembrance in the history of scientific progress--was as follows
in its entirety:—‘Electrical fluid agrees with lightning, in these
particulars: 1. Giving light. 2. The colour of the light. 3. In the
crooked direction of the flame. 4. In the swift motion. 5. In being
conducted by metals. 6. In the crack, or noise, of the explosion. 7.
The subsisting in water, or ice. 8. In the rending of bodies it passes
through. 9. In destroying animals. 10. In melting metals. 11. In firing
inflammable substances. 12. The sulphurous smell. The electric fluid
is attracted by points, and we do not know whether this property is in
lightning. But since they agree in all the particulars wherein we can
already compare them, is it not probable that they agree likewise in
this? _Let the experiment be made._’