[116] Sir William Jones, vol. v. 588. The above may possibly mean a
cross breed of the two beasts, which we find is still practised in
Cabulistan, as related in the Ayeen Akbery.
[117] See Rees’s Cyc. “Strata.”
[118] Hakewill’s Apology, p. 229.
[119] Young. Night VI.
_Description of a cheap and portable Instrument for enabling Young
People to acquire a knowledge of the Stars, or determine their
situation in the Heavens_. By S. Lee, Esq.
There is no science, the study of which tends so much to enlarge the
mind as Astronomy. It opens to our view the grandest examples of
Almighty power, wisdom, and beneficence—the [p372] contemplation
of which fills the soul with reverence and affection for the great
Author of nature, and banishes all narrow and superstitious notions
respecting him.
The cultivation of this science, therefore, cannot be too strongly
recommended to the attention of young people. The eager curiosity
and avidity for discovery which so peculiarly distinguish that
period of life, when the reasoning faculties begin to develope, is
peculiarly fitted for its reception—and, accordingly, amongst the
better-educated classes of society, the elements of this science are
generally considered as a necessary branch of instruction—though
commonly limited to a mere _dogmatic_ explanation of the Copernican
system, and the use of the globes.
But this superficial mode of instruction, though sufficient to enable
any one to understand the real motions of our planetary system, and
explain the apparent motions which must result from them, is hardly
sufficient to satisfy inquisitive reasoning minds, since it leaves
them ignorant of the means by which the distances, magnitudes, and
orbits of the planets and comets were first discovered; and how, if
lost, a knowledge of them might be recovered from observations alone.
The most pleasing methods of instruction will generally be found the
most efficient. It is impossible for any one who has had the least
experience in teaching not to have perceived, that one practical
application of science makes a deeper and more lasting impression on
the mind of a learner than a thousand theoretic propositions.
An accurate knowledge of the fixed stars is the first step to
practical astronomy; it is, in fact, the alphabet of the science. By
the rising, southing, and setting of these bodies, astronomers are
enabled correctly to measure time; and from their apparent altitudes,
to determine the latitude of places on the surface of the globe,
whilst the permanent situations which they maintain with respect to
one another, furnish them with so many marks by which to trace the
course of the sun, moon, and planets through the heavens. Such were
the data which enabled Copernicus and Newton to unravel the seeming
irregularity of their apparent paths, and explain the beautiful
simplicity of their real motions.
The instruments usually had recourse to for this purpose [p373] are,
celestial globes, planispheres, and atlases, but none of these afford
such ready and certain means of finding or identifying particular
fixed stars, as at first might be expected from them.
The Globe possesses the great advantage of being easily rectified
to the place of observation and adjusted to the exact hour of the
night. It likewise exhibits all the stars in their proper situations
of altitude and azimuth;—but the constellations being delineated
on a convex surface, and viewed from without, whilst the heavens
appear to us a concave viewed from within, the groups of stars are
seen reversed, a circumstance which, occasions no small degree of
perplexity to a learner.
Planispheres and atlases exhibit the constellations as they appear to
the eye when on the meridian, but in a position very different from
that which they assume when removed far from it. In short, except the
pleiades and a few remarkable groups, it is difficult to recognise a
constellation in every position, without great practice and continued
observation.
The Equatorial furnishes the best and readiest means of discovering
or identifying any particular star, but the great price of this
instrument, and the complicated nature of its adjustments, render it
unfit for learners.
The instrument which we are about to describe, is in its principle
the same as the Equatorial, though not pretending to any thing like
the same degree of accuracy; but it has this advantage over it,—its
adjustments are more simple and obvious, consequently, better adapted
to the capacity of learners; and it can be afforded at a very
moderate expense, the price not exceeding that of a common globe.
A, B, C, D, is the stand of the instrument, composed of three
triangular pieces of wood glewed together, so that the plane of the
upper piece, D B C, makes with that of the lower piece, A B C, an
angle equal to the co-latitude of the place it is intended for.
On the upper piece, D B C, is described a circle, E F G, the
circumference of which is divided into twenty-four hours, and every
hour into twelve parts, equal to five minutes each.
From the centre of this circle, and perpendicular to the [p374]
plane on which it is described, rises a pillar, the top of which
appears at H above the cone I, which can be made to revolve upon it
as an axis.—On the surface of the cone is delineated the principal
stars visible in England, and the lower edge is divided into 365
parts, representing the days of the year.
[Illustration]
On the top of the pillar is fitted a segment of a circle, K, of
[p375] about 140°: viz. 90° of north, and 40° of south declination,
which may be made to revolve upon the pillar as an axis independently
of the cone. To this part is attached the scale, L, divided into
degrees of north and south declination, corresponding to those on the
semicircle,—and so contrived as in every situation to touch lightly
the surface of the cone.
To the declination circle K is attached the alidade M, which may be
set to any degree required, and serves as an index to direct the eye
of the observer to any object, which may be viewed along the edge of
it, or through the small holes in the sights O P.
Having described the several parts of the instrument, it only remains
to shew the use of it; which will be best explained by means of a few
problems.
PROBLEM 1. To adjust the instrument.
The instrument being made for the place of observation, need only
to be placed on a perfectly horizontal stand, and with the line
joining the hours XII and XII on the circle, in the direction of the
meridian: the former of these adjustments may be verified by means of
a small level applied to the stand at N, in the directions B C and A
N successively. If found incorrect in either position, let a piece
of card be put under that foot (A, B, or C) from which the bubble is
found to recede, and let this operation be repeated until the bubble
rests in the middle, in both positions.
The instrument may be brought into the meridian by the assistance of
a magnetic needle fixed to the frame at N, or on the opposite side,
or more correctly by means of the sun, provided the time be exactly
known, thus:—
Set the index M to the sun’s declination, turn the circle K round
its axis, till the scale L points to the hour and minute on the
circle E F G. Then if the instrument be correctly placed, the sun
will be seen through the sights O, P, or what is the same thing, the
light admitted at the hole O will fall on the hole P. If not, the
instrument must be turned about till this effect is produced.
The instrument being once carefully adjusted to the meridian on any
immoveable stand, such as the sill of a window, [p376] the top of
a post, &c., lines may be drawn on the stand in the direction of
the sides A B, A C, or B C, by means of which it may at any time be
replaced with little trouble.
PROBLEM 2. The instrument being correctly placed and levelled, the
next operation will be to adjust the conical projection to the day
and hour of observation.
Turn the cone round till the day of the month on the circle, at the
bottom of it, coincides with the hour and minute on the circle E F G.
Example.—To adjust the cone for the 15th January, at twenty minutes
past nine at night. Turn the cone till the 15th January on the circle
attached to it coincides with IX h. 20 m. P. M. on the circle E F G.
PROBLEM 3. The cone being adjusted, and any star proposed, to find
its place in the heavens.
The cone remaining at rest, turn the declination segment K till
the scale L cuts the proposed star on the projection; note its
declination on the scale and set the index M to the same degree on
the segment K, when the index will point to the star, which, if the
adjustments have all been correctly made, will be seen through the
sights P, O.
Example.—To find the star Aldebaran; look for Aldebaran on the
projection, bring the scale L to cut it, and you will find it against
16° north declination. Set index M to 16° N. P., and look along the
edge of it, or through the holes P, O, and you will see the star.
PROBLEM 4. Having observed a star in the heavens, to find it on the
projection.
Set the cone as accurately as you can to the day and hour, then turn
the declination segment round, and elevate the index till you can see
the star through the sights P, O. Note the declination at the segment
K, cut by the index M, and against the corresponding degree of the
scale you will find the star on the projection.
If no such star can be found, you may then conclude that it is a
planet, or a new star.
By this means the place of the moon, of a planet, or a comet, may be
noted down, from time to time, and their apparent paths traced out.
[p377]
PROBLEM 5. To find the hour of the day by the sun.
Turn the segment K, and elevate the index M, till the sun is seen or
shines through the sights O, P, and the scale L point to the hour and
minute on the circle E F G.
PROBLEM 6. To find the hour of the night by means of a star.
Direct the index M to the star, so as to be seen through the sights
P, O; then laying hold of the scale L, to keep it in that position,
turn the cone till the star on the projection is cut by the scale,
when the day of the month on the circle at the bottom of the cone
will coincide with the hour and minute on the circle E F G.
This instrument, though not capable of extreme accuracy, might, by
means of careful workmanship, and the addition of a small telescope,
be made sufficiently so for finding stars in the day time; but such a
one as that now described will answer all the purposes of a learner,
and enable very young people to acquire a correct and extensive
knowledge of the stars in a very short time.
The surface of a cone has been adopted for the projection, in
preference to that of a globe or planisphere, having been found,
after repeated trials, the figure best suited to the nature of the
instrument.
_An Introduction to the Comparative Anatomy of Animals, compiled
with constant reference to Physiology, and elucidated by twenty
copper-plates_. By C. J. Carus, M.D., &c. Translated from the
German, by R. T. Gore, Member of the Royal College of Surgeons in
London.
If we except Sir Everard Home’s splendid work on comparative anatomy,
we have no original treatise on that subject which deserves notice;
and even Sir Everard’s lectures must rather be considered as a series
of essays on detached parts of that branch of science, than as a
regular and systematic view of it. We have long been acquainted with
the work of Dr. Carus, and have always considered it as a laborious
and accurate epitome of the principal facts and authorities in the
study to which it relates. From the immense field of inquiry which it
embraces, it is necessarily complicated, and [p378] in some places
a little obscure, but it is entirely free from those speculative
and hypothetical wanderings which are too characteristic of the
German school of physiology; and though it contains some systematic
notions in which we cannot acquiesce, and a few new words, not the
most harmonious in the world, it may very safely and properly be
recommended to the student as a text-book, and to the proficient as
a work of reference. The plates by which it is illustrated are upon
an economical scale, sometimes rather too small to be distinct, but
they are otherwise accurate and carefully drawn; and we are aware
that it is impossible to obviate these objections without incurring
such expense as would probably render the work inaccessible to those
readers for whom it is principally compiled.
Mr. Gore has assiduously and faithfully executed the difficult task
of translation, and has added no inconsiderable quantity of new and
important matter in the form of notes, rendering the English work
more complete, and upon many points much more satisfactory than the
original.
_Experiments to determine the Comparative Value of the principal
varieties of Fuel used in the United States, and also in Europe,
and on the ordinary Apparatus used for their Combustion_. By Marcus
Bull. Philadelphia and London, 1827.
The population of London and its immediate environs may be estimated
at about two millions, and the annual consumption of coals within the
same district does not fall far short of two millions of chaldrons,
or seventy-two millions of bushels. Of this prodigious quantity of
inflammable matter, a very considerable portion escapes combustion,
and lodges in the form of soot in our chimneys, or is vomited forth
to contaminate and cloud the atmosphere of the metropolis: so great
is this loss, that independent of the mere advantage of getting rid
of smoke, its prevention is an important economical problem; and
though the rage for smoke-burning has passed over, we are quite
certain that the subject still deserves the most serious attention,
being convinced that, of the fuel consumed in the ordinary processes
of warming our houses and cooking food, at least one-third is
uselessly thrown away, and might be saved by a more economical and
scientific construction of common grates and fire-places. All useful
and well-conducted experiments, therefore, in [p379] relation to
these matters, deserve notice; and though much of Mr. Bull’s essay
is not applicable to our case, it contains a variety of interesting
facts and information: his experiments appear to have been very
carefully conducted, and should be consulted by all those who are
engaged in similar investigations.
_Meteorological Essays and Observations_. By J. Frederic Daniell,
Esq., F.R.S. Second Part, 1827.
We hope to be able in our next Number to enter into a detailed
examination of the subject of Mr. Daniell’s inquiries; at present,
therefore, our object is merely to announce the second edition of his
valuable and laborious essays, and the publication of the present
_second part_, in which, for the convenience of those who possess
the former edition, all the new matter is collected. It includes the
following essays:—
1. On the Trade winds, considered with reference to Mr. Daniell’s
theory of the constitution of the atmosphere; in a letter from Capt.
Basil Hall, R.N., F.R.S.
2. On evaporation as connected with atmospheric phenomena.
3. On climate, considered with regard to horticulture.
4. On the oscillations of the barometer.
5. On the gradual deterioration of barometers, and the means of
preventing the same.
6. Addenda and notes—among which will be found a valuable table of
the elastic force of aqueous vapour, calculated by Mr. Galbraith from
the experiments of Dr. Ure, by the formula of Mr. Ivory.
_Philosophical Transactions of the Royal Society of London, for the
year 1827_. Part II.
The following are the contents of this Part of the Society’s
Transactions:—
On a new form of the differential thermometer, with some of its
applications. By William Ritchie, A.M., rector of Tain Academy.
Communicated by J. F. W. Herschel, Esq., Sec. R.S.
On the structure and use of the submaxillary odoriferous gland
in the genus Crocodilus. By Thomas Bell, Esq., F.L. and G.S.S.
Communicated by Sir Everard Home, Bart, V.P.R.S.
On the permeability of transparent screens of extreme tenuity of
radiant heat. By William Ritchie, A.M., rector of Tain Academy.
Communicated by J. F. W. Herschel, Esq., Sec. R.S. [p380]
On the derangement of certain transit instruments by the effects of
temperature. By Robert Woodhouse, A.M., F.R.S., &c.
On some of the compounds of chromium. By Thomas Thomson, M.D.,
F.R.S. L. and E., Professor of Chemistry, Glasgow.
Rules and principles for determining the dispersive ratio of
glass; and for computing the radii of curvature for achromatic
object-glasses, submitted to the test of experiment. By Peter
Barlow, Esq., F.R.S., Mem. Imp. Ac. Petrop, &c.
On the change in the plumage of some hen-pheasants. By William
Yarrell, Esq., F.L.S. Communicated by William Morgan, Esq., F.R.S.
On the secondary deflections produced in a magnetised needle by an
iron-shell, in consequence of an unequal distribution of magnetism
in its two branches. First noticed by Captain J. P. Wilson, of the
Honourable East India Company’s ship Hythe. By Peter Barlow, Esq.,
F.R.S., Mem. Imp. Sc. Petrop.
On the difference of meridians of the royal observatories of
Greenwich and Paris. By Thomas Henderson, Esq. Communicated by J. F.
W. Herschel, Esq., Sec. R.S.
Some observations on the effects of dividing the nerves of the
lungs, and subjecting the latter to the influence of voltaic
electricity. By A. P. W. Philip, M.D., F.R.S. L. and E.
On the effects produced upon the air-cells of the lungs when the
pulmonary circulation is too much increased. By Sir Everard Home,
Bart., V.P.R.S.
Theory of the diurnal variation of the magnetic-needle, illustrated
by experiments. By S. H. Christie, Esq., M.A., F.R.S.
On the ultimate composition of simple alimentary substances; with
some preliminary remarks on the analysis of organized bodies in
general. By William Prout, M.D., F.R.S.
_A Practical Treatise on the use of the Blowpipe in chemical and
mineral analysis; including a systematic arrangement of simple
minerals, adapted to aid the student in his progress in mineralogy,
by facilitating the discovery of the names of species_. By John
Griffin, Author of Chemical Recreations. Glasgow, 1827.
Performing with the blowpipe is something like playing upon the
fiddle—it looks mighty easy, but for its perfect accomplishment
requires a combination of skill and dexterity which practice alone
can confer. We are disposed, therefore, to think lightly of those
essays upon the subject which pretend to instruct the beginner in
the actual use of the instrument; telling him how he is to puff out
his cheeks, breathe through his nose, make a valve of his tongue,
and keep up a [p381] perpetual stream through the nozzle of the
tube; all which is much easier described than done, and is entirely
matter of experimental acquisition, more easily attained without
than with the usual instructions. In the little work before us, all
these matters are passed over with fit brevity, and the attention of
the student is chiefly directed to the appearances which different
substances exhibit before the blowpipe, and by which minerals may
be distinguished and classed. The history of these constitute the
bulk of Mr. Griffin’s duodecimo, being preceded only by a few
remarks upon the different kinds of blowpipe, respecting which we
have merely to observe that justice is not done to Mr. Newman, who
first suggested what is here called “Dr. Clarke’s blowpipe;” indeed
elsewhere the author seems a little angry with Mr. Children for
recommending Mr. Newman’s apparatus. We observe, moreover, that no
notice is taken of Mr. Newman’s and several other papers on the
blowpipe, which have appeared in the old series of this Journal; nor
of Dr. Clarke’s original Essay, published in the second volume of
that work, from which, and sundry other symptoms, we conclude that
Mr. Griffin is a pupil of Dr. Thomas Thomson. Be this as it may, we
bear him no malice, and very conscientiously recommend his book to
the mineralogical student, as a valuable and clear epitome of what
relates to the behaviour of substances before the blowpipe.
_Circle of the Seasons, and Perpetual Key to the Calendar and
Almanack; to which is added the Circle of the Hours and History
of the Days of the Week, being a compendious Illustration of the
History, Antiquities, and Natural Phenomena of each Day in the
Year_. London, 1828. Small 8vo.
The title of this book may lead our readers to suspect it as an
interloper among works on science; but it touches upon many points of
scientific inquiry, and upon botany especially, and is compiled with
so much evident labour and accuracy, as to merit recommendation. The
saints and festivals of each day are recorded, by which we make the
acquaintance of many worthy persons and curious anecdotes; there is
also a brief natural history of each day, containing short notices
of the plants which on an average begin to flower or to fade, and
of the birds which arrive or begin to sing. [p382] The merits of
the descriptive poetry, which is thickly interspersed, we leave to
other critics. Those who are destined to live in the “fuliginous
tenebrosity” of this smoke-saturated metropolis, and to breathe an
atmosphere “sated with exhalations rank and fell,” care little about
the first peeping forth of the modest snowdrop, or the early bursting
of the golden crocus; but such as reside in the country will be
glad to have their attention pleasingly directed to the successive
products of the field, the flower-garden, and the green-house.
_Conversations on the Animal Economy_. By a Physician. 2 vols. small
8vo. London, 1827.
We have more than once expressed our opinion on the subject of
conveying information to young people in the way of “Conversations,”
which in the present volumes are carried on between Dr. A., Harriet,
Sophia, and Charles; they are at once instructive and amusing, and
evidently the produce of one possessed of much information upon the
subjects discussed, and, what is more to the point, of the art of
pleasantly and intelligibly conveying it.
The Conversations open with an account of the coverings or
integuments of animals; their arrangements by systematic writers are
then adverted to, and a short but useful description is given of the
varieties of mankind, as enumerated by Blumenbach and illustrated
by Camper. The bones and muscles form the subjects of the fifth
and sixth conversations; they are concisely described, and with
sufficient accuracy. The brain and nervous system and the organs of
sense are next talked about. The doctrines of phrenology are fairly
explained; and in the conversations on smell and taste, vision,
hearing, and touch, the anatomy of the respective organs, and their
varieties in the different animal tribes are treated of, the dulness
of the details being relieved by physiological illustrations. The
remaining conversations are occupied with an account of the principal
functions of animals, and of the several organs chiefly concerned
in their performance; the varieties of teeth and stomachs are here
treated of, and the structures of the heart and blood-vessels, as
concerned in circulation and respiration. The production of heat by
animal systems is then noticed; and the twentieth and concluding
conversation is employed in the exposition of the general phenomena
of growth and decay. [p383]
We have thus briefly stated the contents of these volumes, which
are further illustrated by numerous woodcuts and several plates;
and are perfectly ready to commend the performance as an extremely
useful and proper book for young persons, but _not_, in our opinion,
of both sexes: we should have been better pleased if Harriet and
Sophy had been replaced by William and Thomas; for we cannot fancy
the subjects here discussed as quite fit for young ladies. Boys, on
the contrary, ought to know much more of these matters than they
commonly do; and for conveying such information in a pleasing and
familiar, yet neither vulgar nor superficial style, this compilation
seems perfectly appropriate, and will, we trust, find, as it ought, a
numerous class of readers.