Chapter XIII: Part 13

The demand for Sea-water to supply the Marine Aquarium--now to be seen in so many houses--induced Mr. Gosse to attempt the manufacture of Sea-water, more especially as the constituents are well known. He accordingly took Scheveitzer’s analysis of Sea-water for his guide. In one thousand grains of sea-water taken off Brighton, it gave: water, 964·744; chloride of sodium, 27·059; chloride of magnesium, 3·666; chloride of potassium, 9·755; bromide of magnesium, 0·29; sulphate of magnesia, 2·295; sulphate of lime, 1·407; carbonate of lime, 0·033: total, 999·998. Omitting the bromide of magnesium, the carbonate of lime, and the sulphate of lime, as being very small quantities, the component parts were reduced to common salt, 3½ oz.; Epsom salts, ¼ oz.; chloride of magnesium, 200 grains troy; chloride of potassium, 40 grains troy; and four quarts of water. Next day the mixture was filtered through a sponge into a glass jar, the bottom covered with shore-pebbles and fragments of stone and fronds of green sea-weed. A coating of green spores was soon deposited on the sides of the glass, and bubbles of oxygen were copiously thrown off every day under the excitement of the sun’s light. In a week Mr. Gosse put in species of _Actinia Bowerbankia_, _Cellularia_, _Serpula_, &c. with some red sea-weeds; and the whole throve well.

VELOCITY OF IMPRESSIONS TRANSMITTED TO THE BRAIN.

Professor Helmholtz of Königsberg has, by the electro-magnetic method,[58] ascertained that the intelligence of an impression made upon the ends of the nerves in communication with the skin is transmitted to the brain with a velocity of about 195 feet per second. Arrived at the brain, about one-tenth of a second passes before the will is able to give the command to the nerves that certain muscles shall execute a certain motion, varying in persons and times. Finally, about 1/100th of a second passes after the receipt of the command before the muscle is in activity. In all, therefore, from the excitation of the sensitive nerves till the moving of the muscle, 1¼ to 2/10ths of a second are consumed. Intelligence from the great toe arrives about 1/30th of a second later than from the ear or the face.

Thus we see that the differences of time in the nervous impressions, which we are accustomed to regard as simultaneous, lie near our perception. We are taught by astronomy that, on account of the time taken to propagate light, we now see what has occurred in the fixed stars years ago; and that, owing to the time required for the transmission of sound, we hear after we see is a matter of daily experience. Happily the distances to be traversed by our sensuous perceptions before they reach the brain are so short that we do not observe their influence, and are therefore unprejudiced in our practical interest. With an ordinary whale the case is perhaps more dubious; for in all probability the animal does not feel a wound near its tail until a second after it has been inflicted, and requires another second to send the command to the tail to defend itself.

PHOTOGRAPHS ON THE RETINA.

The late Rev. Dr. Scoresby explained with much minuteness and skill the varying phenomena which presented themselves to him after gazing intently for some time on strongly-illuminated objects,--as the sun, the moon, a red or orange or yellow wafer on a strongly-contrasted ground, or a dark object seen in a bright field. The doctor explained, upon removing the eyes from the object, the early appearance of the picture or image which had been thus “photographed on the Retina,” with the photochromatic changes which the picture underwent while it still retained its general form and most strongly-marked features; also, how these pictures, when they had almost faded away, could at pleasure, and for a considerable time, be renewed by rapidly opening and shutting the eyes.

DIRECT EXPLORATION OF THE INTERIOR OF THE EYE.

Dr. S. Wood of Cincinnati states, that by means of a small double convex lens of short focus held near the eye,--that organ looking through it at a candle twelve or fifteen feet distant,--there will be perceived a large luminous disc, covered with dark and light spots and dark streaks, which, after a momentary confusion, will settle down into an unchanging picture, which picture is composed of the organs or internal parts of the eye. The eye is thus enabled to view its own internal organisation, to have a beautiful exhibition of the vessels of the cornea, of the distribution of the lachrymas secretions in the act of winking, and to see into the nature and cause of _muscæ volitantes_.

NATURE OF THE CANDLE-FLAME.

M. Volger has subjected this Flame to a new analysis.

He finds that the so-called _flame-bud_, a globular blue flaminule,
is first produced at the summit of the wick: this is the result
of the combustion of carbonic oxide, hydrogen, and carbon, and is
surrounded by a reddish-violet halo, the _veil_. The increased
heat now gives rise to the actual flame, which shoots forth from
the expanding bud, and is then surrounded at its inferior portion
only by the latter. The interior consists of a dark gaseous cone,
containing the immediate products of the decomposition of the fatty
acids, and surrounded by another dark hollow cone, the _inner
cap_. Here we already meet with carbon and hydrogen, which have
resulted from the process of decomposition; and we distinguish
this cone from the inner one by its yielding soot. The _external
cap_ constitutes the most luminous portion of the flame, in which
the hydrogen is consumed and the carbon rendered incandescent. The
surrounding portion is but slightly luminous, deposits no soot,
and in it the carbon and hydrogen are consumed.--_Liebig’s Annual
Report._

HOW SOON A CORPSE DECAYS.

Mr. Lewis, of the General Board of Health, from his examination of the contents of nearly 100 coffins in the vaults and catacombs of London churches, concludes that the complete decomposition of a corpse, and its resolution into its ultimate elements, takes place in a leaden coffin with extreme slowness. In a wooden coffin the remains, with the exception of the bones, vanish in from two to five years. This period depends upon the quality of the wood, and the free access of air to the coffins. But in leaden coffins, 50, 60, 80, and even 100 years are required to accomplish this. “I have opened,” says Mr. Lewis, “a coffin in which the corpse had been placed for nearly a century; and the ammoniacal gas formed dense white fumes when brought in contact with hydrochloric-acid gas, and was so powerful that the head could not remain in it for more than a few seconds at a time.” To render the human body perfectly inert after death, it should be placed in a light wooden coffin, in a pervious soil, from five to eight feet deep.

MUSKET-BALLS FOUND IN IVORY.

The Ceylon sportsman, in shooting elephants, aims at a spot just above the proboscis. If he fires a little too low, the ball passes into the tusk-socket, causing great pain to the animal, but not endangering its life; and it is immediately surrounded by osteo-dentine. It has often been a matter of wonder how such bodies should become completely imbedded in the substance of the tusk, sometimes without any visible aperture; or how leaden bullets become lodged in the solid centre of a very large tusk without having been flattened, as they are found by the ivory-turner.

The explanation is as follows: A musket-ball aimed at the head of
an elephant may penetrate the thin bony socket and the thinner
ivory parietes of the wide conical pulp-cavity occupying the
inserted base of the tusk; if the projectile force be there spent,
the ball will gravitate to the opposite and lower side of the
pulp-cavity. The pulp becomes inflamed, irregular calcification
ensues, and osteo-dentine is formed around the ball. The pulp
then resumes its healthy state and functions, and coats the
osteo-dentine enclosing the ball, together with the root of the
conical cavity into which the mass projects, with layers of normal
ivory. The hole formed by the ball is soon replaced, and filled
up by osteo-dentine, and coated with cement. Meanwhile, by the
continued progress of growth, the enclosed ball is pushed forward
to the middle of the solid tusk; or if the elephant be young, the
ball may be carried forward by growth and wear of the tusk until
its base has become the apex, and become finally exposed and
discharged by the continual abrasion to which the apex of the tusk
is subjected.--_Professor Owen._

NATURE OF THE SUN.

To the article at pp. 59-60 should be added the result obtained by Dr. Woods of Parsonstown, and communicated to the _Philosophical Magazine_ for July 1854. Dr. Woods, from photographic experiment, has no doubt that the light from the centre of flame acts more energetically than that from the edge on a surface capable of receiving its impression; and that light from a luminous solid body acts equally powerfully from its centre or its edges: wherefore Dr. Woods concludes that, as the sun affects a sensitive plate similarly with flame, it is probable its light-producing portion is of a similar nature.

_Note to_ “IS THE HEAT OF THE SUN DECREASING?” _at page 65_.--Dr.
Vaughan of Cincinnati has stated to the British Association:
“From a comparison of the relative intensity of solar, lunar,
and artificial light, as determined by Euler and Wollaston, it
appears that the rays of the sun have an illuminating power
equal to that of 14,000 candles at a distance of one foot, or
of 3500,000000,000000,000000,000000 candles at a distance of
95,000,000 miles. It follows that the amount of light which
flows from the solar orb could be scarcely produced by the daily
combustion of 200 globes of tallow, each equal to the earth in
magnitude. A sphere of combustible matter much larger than the
sun itself should be consumed every ten years in maintaining its
wonderful brilliancy; and its atmosphere, if pure oxygen, would be
expended before a few days in supporting so great a conflagration.
An illumination on so vast a scale could be kept up only by the
inexhaustible magazine of ether disseminated through space, and
ever ready to manifest its luciferous properties on large spheres,
whose attraction renders it sufficiently dense for the play of
chemical affinity. Accordingly suns derive the power of shedding
perpetual light, not from their chemical constitution, but from
their immense mass and their superior attractive power.”

PLANETOIDS.

+----------------+---------------+-----------+-----------+-----------+
| | | | | No. |
| | | | |discovered |
| | Date of | | Place of | by each |
| Name. | Discovery. |Discoverer.| Discovery.|astronomer.|
+----------------+---------------+-----------+-----------+-----------+
|Mercury, Mars, }| Known } | | | |
|Venus, Jupiter,}| to the } | ... | ... | -- |
|Earth, Saturn, }| ancients.} | | | |
| Uranus |1781, March 13 |W. Herschel| Bath | -- |
| Neptune[59] |1846, Sept. 23 |Galle | Berlin | -- |
| 1 Ceres |1801, Jan. 1 |Piazzi | Palermo | 1 |
| 2 Pallas |1802, March 28 |Olbers | Bremen | 1 |
| 3 Juno |1804, Sept. 1 |Harding | Lilienthal| 1 |
| 4 Vesta |1807, March 29 |Olbers | Bremen | 2 |
| 5 Astræa |1845, Dec. 8 |Encke | Driesen | 1 |
| 6 Hebe |1847, July 1 |Encke | Driesen | 2 |
| 7 Iris |1847, August 13|Hind | London | 1 |
| 8 Flora |1847, Oct. 18 |Hind | London | 2 |
| 9 Metis |1848, April 25 |Graham | Markree | 1 |
|10 Hygeia |1849, April 12 |Gasperis | Naples | 1 |
|11 Parthenope |1850, May 11 |Gasperis | Naples | 2 |
|12 Victoria |1850, Sept. 13 |Hind | London | 3 |
|13 Egeria |1850, Nov. 2 |Gasperis | Naples | 3 |
|14 Irene |1851, May 19 |Hind | London | 4 |
|15 Eunomia |1851, July 29 |Gasperis | Naples | 4 |
|16 Psyche |1852, March 17 |Gasperis | Naples | 5 |
|17 Thetis |1852, April 17 |Luther | Bilk | 1 |
|18 Melpomene |1852, June 24 |Hind | London | 5 |
|19 Fortuna |1852, August 22|Hind | London | 6 |
|20 Massilia |1852, Sept. 19 |Gasperis | Naples | 6 |
|21 Lutetia |1852, Nov. 15 |Goldschmidt| Paris | 1 |
|22 Calliope |1852, Nov. 16 |Hind | London | 7 |
|23 Thalia |1852, Dec. 15 |Hind | London | 8 |
|24 Themis |1853, April 5 |Gasperis | Naples | 7 |
|25 Phocea |1853, April 6 |Chacornac | Marseilles| 1 |
|26 Proserpine |1853, May 5 |Luther | Bilk | 2 |
|27 Euterpe |1853, Nov. 8 |Hind | London | 9 |
|28 Bellona |1854, March 1 |Luther | Bilk | 3 |
|29 Amphitrite |1854, March 1 |Marth | London | 1 |
|30 Urania |1854, July 22 |Hind | London | 10 |
|31 Euphrosyne |1854, Sept. 1 |Furguson | Washington| 1 |
|32 Pomona |1854, Oct. 26 |Goldschmidt| Paris | 2 |
|33 Polyhymnia |1854, Oct. 28 |Chacornac | Paris | 2 |
|34 Circe |1855, April 6 |Chacornac | Paris | 3 |
|35 Leucothea |1855, April 19 |Luther | Bilk | 4 |
|36 Atalante |1855, Oct. 5 |Goldschmidt| Paris | 3 |
|37 Fides |1855, Oct. 5 |Luther | Bilk | 5 |
|38 Leda |1856, Jan. 12 |Chacornac | Paris | 4 |
|39 Lætitia |1856, Feb. 8 |Chacornac | Paris | 5 |
|40 Harmonia |1856, March 31 |Goldschmidt| Paris | 4 |
|41 Daphne |1856, May 22 |Goldschmidt| Paris | 5 |
|42 Isis |1856, May 23 |Pogson | Oxford | 1 |
|43 Ariadne |1857, April 15 |Pogson | Oxford | 2 |
|44 Nysa |1857, May 27 |Goldschmidt| Paris | 6 |
|45 Eugenia |1857, June 28 |Goldschmidt| Paris | 7 |
|46 Hastia |1857, August 16|Pogson | Oxford | 3 |
|47 Aglaia |1857, Sept. 15 |Luther | Bilk | 6 |
|48 Doris |1857, Sept. 19 |Goldschmidt| Paris | 8 |
|49 Pales |1857, Sept. 19 |Goldschmidt| Paris | 9 |
|50 Virginia |1857, Oct. 4 |Furguson | Washington| 2 |
|51 Nemausa |1858, Jan. 22 |Laurent | Nismes | 1 |
|52 Europa |1858, Feb. 6 |Goldschmidt| Paris | 10 |
|53 Calypso |1858, April 8 |Luther | Bilk | 7 |
|54 Alexandra |1858, Sept. 11 |Goldschmidt| Paris | 11 |
|55 (Not named) |1858, Sept. 11 |Searle | Albany | 1 |
+----------------+---------------+-----------+-----------+-----------+

THE COMET OF DONATI.

While this sheet was passing through the press, the attention of astronomers, and of the public generally, was drawn to the fact of the above Comet passing (on Oct. 18) within nine millions of miles of the planet Venus, or less than 9/100ths of the earth’s distance from the Sun. “And (says Mr. Hind, the astronomer), it is obvious that if the comet had reached its least distance from the sun a few days earlier than it has done, the planet might have passed through it; and I am very far from thinking that close proximity to a comet of this description would be unattended with danger. The inhabitants of Venus will witness a cometary spectacle far superior to that which has recently attracted so much attention here, inasmuch as the tail will doubtless appear twice as long from that planet as from the earth, and the nucleus proportionally more brilliant.”

This Comet was first discovered by Dr. G. B. Donati, astronomer at the Museum of Florence, on the evening of the 2d of June, in right ascension 141° 18′, and north declination 23° 47′, corresponding to a position near the star Leonis. Previous to this date we had no knowledge of its existence, and therefore it was not a predicted comet; neither is it the one last observed in 1556. At the date of discovery it was distant from the earth 228,000,000 of miles, and was an excessively faint object in the largest telescopes.

The tail, from October 2 to 16, when the comet was most conspicuous, appears to have maintained an average length of at least 40,000,000 miles, subtending an angle varying from 30° to 40°. The dark line or space down the centre, frequently remarked in other great comets, was a striking characteristic in that of Donati. The nucleus, though small, was intensely brilliant in powerful instruments, and for some time bore high magnifiers to much greater advantage than is usual with these objects. In several respects this comet resembled the famous ones of 1744, 1680, and 1811, particularly as regards the signs of violent agitation going on in the vicinity of the nucleus, such as the appearance of luminous jets, spiral offshoots, &c., which rapidly emanated from the planetary point and as quickly lost themselves in the general nebulosity of the head.

On the 5th Oct. the most casual observer had an opportunity of satisfying himself as to the accuracy of the mathematical theory of the motions of comets in the near approach of the nucleus of Donati’s to Arcturus, the principal star in the constellation Bootes. The circumstance of the appulse was very nearly as predicted by Mr. Hind.

The comet, according to the investigations by M. Loewy, of the Observatory of Vienna, arrived at its least distance from the sun a few minutes after eleven o’clock on the morning of the 30th of September; its longitude, as seen from the sun at this time, being 36° 13′, and its distance from him 55,000,000 miles. The longer diameter of its orbit is 184 times that of the earth’s, or 35,100,000,000 miles; yet this is considerably less than 1/1000th of the distance of the nearest fixed star. As an illustration, let any one take a half-sheet of note-paper, and marking a circle with a sixpence in one corner of it, describe therein our solar system, drawing the orbits of the earth and the inferior planets as small as he can by the aid of a magnifying-glass. If the circumference of the sixpence stands for the orbit of Neptune, then an oval filling the page will fairly represent the orbit of Donati’s comet; and if the paper be laid upon the pavement under the west door of St. Paul’s Cathedral, London, the length of that edifice will inadequately represent the distance of the nearest fixed star. The time of revolution resulting from Mr. Loewy’s calculations is 2495 years, which is about 500 years less than that of the comet of 1811 during the period it was visible from the earth.

That the comet should take more than 2000 years to travel round the above page of note-paper is explained by its great diminution of speed as it recedes from the sun. At its perihelion it travelled at the rate of 127,000 miles an hour, or more than twice as fast as the earth, whose motion is about 1000 miles a minute. At its aphelion, however, or its greatest distance from the sun, the comet is a very slow body, sailing at the rate of 480 miles an hour, or only eight times the speed of a railway express. At this pace, were it to travel onward in a straight line, the lapse of a million of years would find it still travelling half way between our sun and the nearest fixed star.

As this comet last visited us between 2000 and 2495 years since, we know that its appearance was at an interesting period of the world’s history. It might have terrified the Athenians into accepting the bloody code of Draco. It might have announced the destruction of Nineveh, or of Babylon, or the capture of Jerusalem by Nebuchadnezzar. It might have been seen by the expedition which sailed round Africa in the reign of Pharaoh Necho. It might have given interest to the foundation of the Pythian games. Within the probable range of its last visitation are comprehended the whole of the great events of the history of Greece; and among the spectators of the comet may have been the so-called sages of Greece and even the prophets of Holy Writ: Thales might have attempted to calculate its return, and Jeremiah might have tried to read its warning.--_Abridged from a Communication from Mr. Hind to the Times, and from a Leader in that Journal._

FOOTNOTES:

[1] From a photograph, with figures, to show the relative size of the tube aperture.

[2] Weld’s _History of the Royal Society_, vol. ii. p. 188.

[3] Dr. Whewell (_Bridgewater Treatise_, p. 266) well observes, that Boyle and Pascal are to hydrostatics what Galileo is to mechanics, and Copernicus, Kepler, and Newton are to astronomy.

[4] The Rev. Mr. Turnor recollects that Mr. Jones, the tutor, mentioned, in one of his lectures on optics, that the reflecting telescope belonging to Newton was then lodged in the observatory over the gateway; and Mr. Turnor thinks that he once saw it, with a finder affixed to it.

[5] The story of the dog “Diamond” having caused the burning of certain papers is laid in London, and in Newton’s later years. In the notes to Maude’s _Wenleysdale_, a person then living (1780) relates, that Sir Isaac being called out of his study to a contiguous room, a little dog, called Diamond, the constant but incurious attendant of his master’s researches, happened to be left among the papers, and by a fatality not to be retrieved, as it was in the latter part of Sir Isaac’s days, threw down a lighted candle, which consumed the almost finished labour of some years. Sir Isaac returning too late but to behold the dreadful wreck, rebuked the author of it with an exclamation (_ad sidera palmas_), “O Diamond! Diamond! thou little knowest the mischief done!” without adding a single stripe. M. Biot gives this fiction as a true story, which happened some years after the publication of the _Principia_; and he characterises the accident as having deprived the sciences forever of the fruit of so much of Newton’s labours.--Brewster’s _Life_, vol. ii. p. 139, note. Dr. Newton remarks, that Sir Isaac never had any communion with dogs or cats; and Sir David Brewster adds, that the view which M. Biot has taken of the idle story of the dog Diamond, charged with fire-raising among Newton’s manuscripts, and of the influence of this accident upon the mind of their author, is utterly incomprehensible. The fiction, however, was turned to account in giving colour to M. Biot’s misrepresentation.

[6] Bohn’s edition.

[7] When at Pisa, many years since, Captain Basil Hall investigated the origin and divergence of the tower from the perpendicular, and established completely to his own satisfaction that it had been built from top to bottom originally just as it now stands. His reasons for thinking so were, that the line of the tower, on that side towards which it leans, has not the same curvature as the line on the opposite, or what may be called the upper side. If the tower had been built upright, and then been made to incline over, the line of the wall on that side towards which the inclination was given would be more or less concave in that direction, owing to the nodding or “swagging over” of the top, by the simple action of gravity acting on a very tall mass of masonry, which is more or less elastic when placed in a sloping position. But the contrary is the fact; for the line of wall on the side towards which the tower leans is decidedly more convex than the opposite side. Captain Hall had therefore no doubt whatever that the architect, in rearing his successive courses of stones, gained or stole a little at each layer, so as to render his work less and less overhanging as he went up; and thus, without betraying what he was about, really gained stability.--See _Patchwork_.

[8] Lord Bacon proposed that, in order to determine whether the gravity of the earth arises from the gravity of its parts, a clock-pendulum should be swung in a mine, as was recently done at Harton colliery by the Astronomer-Royal.

When, in 1812, Ampère noted the phenomena of the pendulum, and showed that its movement was produced only when the eye of the observer was fixed on the instrument, and endeavoured to prove thereby that the motion was due to a play of the muscles, some members of the French Academy objected to the consideration of a subject connected to such an extent with superstition.

[9] This curious fact was first recorded by Pepys, in his _Diary_, under the date 31st of July 1665.

[10] The result of these experiments for ascertaining the variation of the gravity at great depths, has proved beyond doubt that the attraction of gravitation is increased at the depth of 1250 feet by 1/19000 part.

[11] See the account of Mr. Baily’s researches (with two illustrations) in _Things not generally Known_, p. vii., and “Weight of the Earth,” p. 16.

[12] Fizeau gives his result in leagues, reckoning twenty-five to the equatorial degree. He estimates the velocity of light at 70,000 such leagues, or about 210,000 miles in the second.

[13] See _Things not generally Known_, p. 88.

[14] Some time before the first announcement of the discovery of sun-painting, the following extract from Sir John Herschel’s _Treatise on Light_, in the _Encyclopædia Metropolitana_, appeared in a popular work entitled _Parlour Magic_: “Strain a piece of paper or linen upon a wooden frame, and sponge it over with a solution of nitrate of silver in water; place it behind a painting upon glass, or a stained window-pane, and the light, traversing the painting or figures, will produce a copy of it upon the prepared paper or linen; those parts in which the rays were least intercepted being the shadows of the picture.”

[15] In his book on Colours, Mr. Doyle informs us that divers, if not all, essential oils, as also spirits of wine, when shaken, “have a good store of bubbles, which appear adorned with various and lively colours.” He mentions also that bubbles of soap and turpentine exhibit the same colours, which “vary according to the incidence of the sight and the position of the eye;” and he had seen a glass-blower blow bubbles of glass which burst, and displayed “the varying colours of the rainbow, which were exceedingly vivid.”

[16] The original idea is even attributed to Copernicus. M. Blundevile, in his _Treatise on Cosmography_, 1594, has the following passage, perhaps the most distinct recognition of authority in our language: “How prooue (prove) you that there is but one world? By the authoritie of Aristotle, who saieth that if there were any other world out of this, then the earth of that world would mooue (move) towards the centre of this world,” &c.

Sir Isaac Newton, in a conversation with Conduitt, said he took “all the planets to be composed of the same matter with the earth, viz. earth, water, and stone, but variously concocted.”

[17] Sir William Herschel ascertained that our solar system is advancing towards the constellation Hercules, or more accurately to a point in space whose right ascension is 245° 52′ 30″, and north polar distance 40° 22′; and that the quantity of this motion is such, that to an astronomer placed in Sirius, our sun would appear to describe an arc of little more than _a second_ every year.--_North-British Review_, No. 3.

[18] See M. Arago’s researches upon this interesting subject, in _Things not generally Known_, p. 4.

[19] This eloquent advocacy of the doctrine of “More Worlds than One” (referred to at p. 51) is from the author’s valuable _Outlines of Astronomy_.

[20] Professor Challis, of the Cambridge Observatory, directing the Northumberland telescope of that institution to the place assigned by Mr. Adams’s calculations and its vicinity on the 4th and 12th of August 1846, saw the planet on both those days, and noted its place (among those of other stars) for re-observation. He, however, postponed the _comparison_ of the places observed, and not possessing Dr. Bremiker’s chart (which would at once have indicated the presence of an unmapped star), remained in ignorance of the planet’s existence as a visible object till the announcement of such by Dr. Galle.

[21] For several interesting details of Comets, see “Destruction of the World by a Comet,” in _Popular Errors Explained and Illustrated_, new edit. pp. 165-168.

[22] The letters of Sir Isaac Newton to Dr. Bentley, containing suggestions for the Boyle Lectures, possess a peculiar interest in the present day. “They show” (says Sir David Brewster) “that the _nebular hypothesis_, the dull and dangerous heresy of the age, is incompatible with the established laws of the material universe, and that an omnipotent arm was required to give the planets their positions and motions in space, and a presiding intelligence to assign to them the different functions they had to perform.”--_Life of Newton_, vol. ii.

[23] The constitution of the nebulæ in the constellation of Orion has been resolved by this instrument; and by its aid the stars of which it is composed burst upon the sight of man for the first time.

[24] Several specimens of Meteoric Iron are to be seen in the Mineralogical Collection in the British Museum.

[25] _Life of Sir Isaac Newton_, vol. i. p. 62.

[26] _Description of the Monster Telescope_, by Thomas Woods, M.D. 4th edit. 1851.

[27] This instrument also discovered a multitude of new objects in the moon; as a mountainous tract near Ptolemy, every ridge of which is dotted with extremely minute craters, and two black parallel stripes in the bottom of Aristarchus. Dr. Robinson, in his address to the British Association in 1843, stated that in this telescope a building the size of the Court-house at Cork would be easily visible on the lunar surface.

[28] Mr. Hopkins supports his Glacial Theory by regarding the _Waves of Translation_, investigated by Mr. Scott Russell, as furnishing a sufficient moving power for the transportation of large rounded boulders, and the formation of drifted gravel. When these waves of translation are produced by the sudden elevation of the surface of the sea, the whole mass of water from the surface to the bottom of the ocean moves onward, and becomes a mechanical agent of enormous power. Following up this view, Mr. Hopkins has shown that “elevations of continental masses of only 50 feet each, and from beneath an ocean having a depth of between 300 and 400 feet, would cause the most powerful divergent waves, which could transport large boulders to great distances.”

[29] It is scarcely too much to say, that from the collection of specimens of building-stones made upon this occasion, and first deposited in a house in Craig’s Court, Charing Cross, originated, upon the suggestion of Sir Henry Delabeche, the magnificent Museum of Practical Geology in Jermyn Street; one of the most eminently practical institutions of this scientific age.

[30] Mr. R. Mallet, F.R.S., and his son Dr. Mallet, have constructed a seismographic map of the world, with seismic bands in their position and relative intensity; and small black discs to denote volcanoes, femaroles, and soltataras, and shades indicating the areas of subsidence.

[31] It has been computed that the shock of this earthquake pervaded an area of 700,000 miles, or the twelfth part of the circumference of the globe. This dreadful shock lasted only five minutes; and nearly the whole of the population being within the churches (on the feast of All Saints), no less than 30,000 persons perished by the fall of these edifices.--See _Daubeny on Volcanoes_; _Translator’s note, Humboldt’s Cosmos_.

[32] Mr. Murray mentions, on the authority of the Rev. Dr. Robinson, of the Observatory at Armagh, that a rough diamond with a red tint, and valued by Mr. Rundell at twenty guineas, was found in Ireland, many years since, in the bed of a brook flowing through the county of Fermanagh.

[33] The use of malachite in ornamental work is very extensive in Russia. Thus, to the Great Exhibition of 1851 were sent a pair of folding-doors veneered with malachite, 13 feet high, valued at 6000_l._; malachite cases and pedestals from 1500_l._ to 3000_l._ a-piece, malachite tables 400_l._, and chairs 150_l._ each.

[34] Longfellow has written some pleasing lines on “The Fiftieth Birthday of M. Agassiz. May 28, 1857,” appended to “The Courtship of Miles Standish,” 1858.

[35] The _sloth_ only deserves its name when it is obliged to attempt to proceed along the ground; when it has any thing which it can lay hold of it is agile enough.

[36] Dr. A. Thomson has communicated to _Jameson’s Journal_, No. 112, a Description of the Caves in the North Island, with some general observations on this genus of birds. He concludes them to have been indolent, dull, and stupid; to have lived chiefly on vegetable food in mountain fastnesses and secluded caverns.

In the picture-gallery at Drayton Manor, the seat of Sir Robert Peel, hangs a portrait of Professor Owen, and in his hand is depicted the tibia of a Moa.

[37] According to the law of correlation, so much insisted on by Cuvier, a superior character implies the existence of its inferiors, and that too in definite proportions and constant connections; so that we need only the assurance of one character, to be able to reconstruct the whole animal. The triumph of this system is seen in the reconstruction of extinct animals, as in the above case of the Dinornis, accomplished by Professor Owen.

[38] Not only at London, but at Paris, Vienna, Berlin, Turin. St. Petersburg, and almost every other capital in Europe; at Liege, Caen, Montpellier, Toulouse, and several other large towns,--wherever, in fact, there are not great local obstacles,--the tendency of the wealthier inhabitants to group themselves to the west is as strongly marked as in the British metropolis. At Pompeii, and other ancient towns, the same thing maybe noticed; and where the local configuration of the town necessitates an increase in a different direction, the moment the obstacle ceases houses spread towards the west.

[39] By far the most complete set of experiments on the Radiation of Heat from the Earth’s Surface at Night which have been published since Dr. Wells’s Memoir _On Dew_, are those of Mr. Glaisher, F.R.S., _Philos. Trans._ for 1847.

[40] The author is largely indebted for the illustrations in this new field of research to Lieutenant Maury’s valuable work, _The Physical Geography of the Sea_. Sixth edition. Harper, New York; Low, Son, and Co., London.

[41] It is the chloride of magnesia which gives that damp sticky feeling to the clothes of sailors that are washed or wetted with salt water.

[42] This fraction rests on the assumption that the dilatation of the substances of which the earth is composed is equal to that of glass, that is to say, 1/18000 for 1°. Regarding this hypothesis, see Arago, in the _Annuaire_ for 1834, pp. 177-190.

[43] Electricity, traversing excessively rarefied air or vapours, gives out light, and doubtless also heat. May not a continual current of electric matter be constantly circulating in the sun’s immediate neighbourhood, or traversing the planetary spaces, and exerting in the upper regions of its atmosphere those phenomena of which, on however diminutive a scale, we have yet an unequivocal manifestation in our Aurora Borealis?

[44] Could we by mechanical pressure force water into a solid state, an immense quantity of heat would be set free.

[45] See Mr. Hunt’s popular work, _The Poetry of Science; or, Studies of Physical Phenomena of Nature_. Third edition, revised and enlarged. Bohn, 1854.

[46] Canton was the first who in England verified Dr. Franklin’s idea of the similarity of lightning and the electric fluid, July 1752.

[47] This is mentioned in _Procli Diadochi Paraphrasis Ptolem._, 1635. (Delambre, _Hist. de l’Astronomie ancienne_.)

[48] The first Variation-Compass was constructed, before 1525, by an ingenious apothecary of Seville, Felisse Guillen. So earnest were the endeavours to learn more exactly the direction of the curves of magnetic declination, that in 1585 Juan Jayme sailed with Francisco Gali from Manilla to Acapulco, for the sole purpose of trying in the Pacific a declination instrument which he had invented.--_Humboldt._

[49] Gilbert was surgeon to Queen Elizabeth and James I., and died in 1603. Whewell justly assigns him an important place among the “practical reformers of the physical sciences.” He adopted the Copernican doctrine, which Lord Bacon’s inferior aptitude for physical research led him to reject.

[50] This illustration, it will be seen, does not literally correspond with the details which precede it.

[51] Mr. Crosse gave to the meeting a general invitation to Fyne Court; one of the first to accept which was Sir Richard Phillips, who, on his return to Brighton, described in a very attractive manner, at the Sussex Institution, Mr. Crosse’s experiments and apparatus; a report of which being communicated to the _Brighton Herald_, was quoted in the _Literary Gazette_, and thence copied generally into the newspapers of the day.

[52] These experiments were performed at the expense of the Royal Society, and cost 10_l._ 5_s._ 6_d._ In the Paper detailing the experiments, printed in the 45th volume of the _Philosophical Transactions_, occurs the first mention of Dr. Franklin’s name, and of his theory of positive and negative electricity.--_Weld’s Hist. Royal Soc._ vol. i. p. 467.

[53] In this year Andrew Crosse said: “I prophesy that by means of the electric agency we shall be enabled to communicate our thoughts instantaneously with the uttermost parts of the earth.”

[54] To which paper the writer is indebted for many of these details.

[55] These illustrations have been in the main selected and abridged from papers in the _Companion to the Almanac_, 1858, and the _Penny Cyclopædia_, 2d supp.

[56] Newton was, however, much pestered with inquirers; and a Correspondent of the _Gentleman’s Magazine_, in 1784, relates that he once had a transient view of a Ms. in Pope’s handwriting, in which he read a verified anecdote relating to the above period. Sir Isaac being often interrupted by ignorant pretenders to the discovery of the longitude, ordered his porter to inquire of every stranger who desired admission whether he came about the longitude, and to exclude such as answered in the affirmative. Two lines in Pope’s Ms., as the Correspondent recollects, ran thus:

“‘Is it about the longitude you come?’
The porter asks: ‘Sir Isaac’s not at home.’”

[57] In trying the merits of Harrison’s chronometers, Dr. Maskelyne acquired that knowledge of the wants of nautical astronomy which afterwards led to the formation of the Nautical Almanac.

[58] A slight electric shock is given to a man at a certain portion of the skin; and he is directed the moment he feels the stroke to make a certain motion, as quickly as he possibly can, with the hands or with the teeth, by which the time-measuring current is interrupted.

[59] Through the calculations of M. Le Verrier.

GENERAL INDEX

Abodes of the Blest, 58.

Acarus of Crosse and Weeks, 218.

Accuracy of Chinese Observers, 159.

Adamant, What was it?, 123.

Aeronautic Voyage, Remarkable, 169.

Agassiz, Discoveries of, 127.

Air, Weight of, 14.

All the World in Motion, 11.

Alluvial Land of Egypt, 110.

Ancient World, Science of the, 1.

Animals in Geological Times, 128.

Anticipations of the Electric Telegraph, 220-224.

Arago on Protection from Storms, 159.

Arctic Climate, Phenomena of, 162.

Arctic Explorations, Rae’s, 162.

Arctic Regions, Scenery and Life of, 180.

Arctic Temperature, 161.

Armagh Observatory Level, Change of, 144.

Artesian Fire-Springs, 118.

Artesian Well of Grenelle, 114.

Astronomer, Peasant, 101.

Astronomer’s Dream verified, 88.

Astronomers, Triad of Contemporary, 100.

Astronomical Observations, Nicety of, 102.

Astronomy and Dates on Monuments, 55.

Astronomy and Geology, Identity of, 104.

Astronomy, Great Truths of, 54.

Atheism, Folly of, 3.

Atlantic, Basin of the, 171.

Atlantic, Gales of the, 171.

Atlantic Telegraph, the, 226-228.

Atmosphere, Colours of the, 147.

Atmosphere compared to a Steam-engine, 152.

Atmosphere, Height of, 147.

Atmosphere, the, 146.

Atmosphere, the purest, 150.

Atmosphere, Universality of the, 147.

Atmosphere weighed by Pascal, 148.

Atoms of Elementary Bodies, 13.

Atoms, the World of, 13.

Aurora Borealis, Halley’s hypothesis of, 198.

Aurora Borealis, Splendour of the, 165.

Australian Cavern, Inmates of, 137.

Australian Pouch-Lion, 137.

Axis of Rotation, the, 11.

Barometer, Gigantic, 151.

Barometric Measurement, 151.

Batteries, Minute and Vast, 204.

Birds, Gigantic, of New Zealand, Extinct, 139.

“Black Waters, the,” 182.

Bodies, Bright, the Smallest, 31.

Bodies, Compression of, 12.

Bodies, Fall of, 16.

Bottles and Currents at Sea, 172.

Boulders, How transported to Great Heights, 105.

Boyle on Colours, 49.

Boyle, Researches of, 6.

Brain, Impressions transmitted to, 235.

Buckland, Dr., his Geological Labours, 127.

Building-Stone, Wear of, 108.

Burnet’s Theory of the Earth, 125.

Bust, Magic, 36.

Candle-flame, Nature of, 237.

Canton’s Artificial Magnets, 196.

Carnivora of Britain, Extinct, 132.

Carnivores, Monster, of France, 138.

Cataract, Great, in India, 183.

Cat, Can it see in the Dark?, 51.

Caves of New Zealand and its Gigantic Birds, 140.

Cave Tiger or Lion of Britain, 133.

Central Heat, Theory of, 116.

Chabert, “the Fire King,” 192.

Chalk Formation, the, 108.

Changes on the Earth’s Surface, 142.

Chantrey, Heat-Experiments by, 192.

Children’s powerful Battery, 204.

Chinese, the, and the Magnetic Needle, 194.

Chronometers, Marine, How rated at Greenwich Observatory, 229.

Climate, finest in the World, 149.

Climate, Variations of, 148.

Climates, Average, 149.

Clock, How to make Electric, 212.

Cloud-ring, the Equatorial, 156.

Clouds, Fertilisation of, 151.

Coal, Torbane-Hill, 123.

Coal, What is it?, 123.

Cold in Hudson’s Bay, 160.

Colour of a Body, and its Magnetic Properties, 197.

Colours and Tints, Chevreul on, 37.

Colours most frequently hit in Battle, 36.

Comet, the, of Donati, 240, 241.

Comet, Great, of 1843, 84.

Comets, Magnitude of, 84.

Comets visible in Sunshine, 84.

Computation, Power of, 10.

Coney of Scripture, 137.

Conic Sections, 10.

Continent Outlines not fixed, 145.

Corpse, How soon it decays, 237.

“Cosmos, Science of the,” 10.

Crosse, Andrew, his Artificial Crystals and Minerals, 216-219.

Crosse Mite, the, 218.

Crystallisation, Reproductive, 26.

Crystallisation, Theory of, 24.

Crystallisation, Visible, 25.

Crystals, Immense, 24.

“Crystal Vault of Heaven,” 55.

Davy, Sir Humphry, obtains Heat from Ice, 190.

Davy’s great Battery at the Royal Institution, 204.

Day, Length of, and Heat of the Earth, 186.

Day’s Length at the Poles, 65.

Declination of the Needle, 197.

Descartes’ Labours in Physics, 9.

Desert, Intense Heat and Cold of the, 163.

Dew-drop, Beauty of the, 157.

Dew-fall in one year, 157.

Dew graduated to supply Vegetation, 157.

Diamond, Geological Age of, 122.

Diamond Lenses for Microscopes, 40.

“Diamond,” Newton’s Dog, 8.

Dinornis elephantopus, the, 139, 140.

Dinotherium, or Terrible Beast, the, 136.

Diorama, Illusion of the, 37.

Earth and Man compared, 22.

Earth, Figure of the, 21.

Earth, Mass and Density of, 21.

Earth’s Annual Motion, 12.

Earth’s Magnitude, to ascertain, 21.

Earth’s Surface, Mean Temperature of, 23.

Earth’s Temperature, Interior, 116.

Earth’s Temperature Stationary, 23.

Earth, the, a Magnet, 197.

Earthquake, the Great Lisbon, 121.

Earthquakes and the Moon, 121.

Earthquakes, Rumblings of, 120.

Earthquake-Shock, How to measure, 120.

Earth-Waves, 119.

Eclipses, Cause of, 74.

Egypt, Alluvial Land of, 110.

Electric Girdle for the Earth, 224.

Electric Incandescence of Charcoal Points, 204.

Electric Knowledge, Germs of, 207.

Electric Light, Velocity of, 209.

Electric Messages, Time lost in, 225.

Electric Paper, 209.

Electric Spark, Duration of, 209.

Electric Telegraph, Anticipations of the, 220-224.

Electric Telegraph, Consumption of, 224.

Electric Telegraph in Astronomy and Longitude, 225.

Electric Telegraph and Lightning, 226.

Electric and Magnetic Attraction, Identity of, 210.

Electrical Kite, Franklin’s, 213.

Electricity and Temperature, 208.

Electricity in Brewing, 209.

Electricity, Vast Arrangement of, 208.

Electricity, Water decomposed by, 208.

Electricities, the Two, 214.

Electro-magnetic Clock, Wheatstone’s, 211.

Electro-magnetic Engine, Theory of, 210.

Electro-magnets, Horse-shoe, 199.

Electro-telegraphic Message to the Stars, 226.

Elephant and Tortoise of India, 135.

End of our System, 92.

England in the Eocene Period, 129.

English Channel, Probable Origin of, 105.

Eocene Period, the, 129.

Equatorial Cloud-ring, 156.

“Equatorial Doldrums,” 156.

Error upon Error, 185.

Exhilaration in ascending Mountains, 163.

Eye and Brain seen through a Microscope, 41.

Eye, interior, Exploration of, 236.

Fall of Bodies, Rate of, 16.

Falls, Height of, 16.

Faraday, Genius and Character of, 193.

Faraday’s Electrical Illustrations, 214.

“Father of English Geology, the,” 126.

Fertilisation of Clouds, 151.

Fire, Perpetual, 117.

Fire-balls and Shooting Stars, 89.

Fire-Springs, Artesian, 118.

Fishes, the most Ancient, 132.

Flying Dragon, the, 130.

Force neither created nor destroyed, 18.

Force of Running Water, 114.

Fossil Human Bones, 131.

Fossil Meteoric Stones, none, 92.

Fossil Rose, none, 142.

Foucault’s Pendulum Experiments, 22.

Franklin’s Electrical Kite, 213.

Freezing Cavern in Russia, 115.

Fresh Water in Mid-Ocean, 182.

Galilean Telescope, the, 93.

Galileo, What he first saw with the Telescope, 93.

Galvani and Volta, 205.

Galvanic Effects, Familiar, 203.

Galvanic Waves on the same Wire, Non-interference of, 225.

“Gauging the Heavens,” 58.

Genius, Relics of, 5.

Geology and Astronomy, Identity of, 104.

Geology of England, 105.

Geological Time, 143.

George III., His patronage of Herschel, 95.

Gilbert on Magnetic and Electric forces, 201.

Glacial Theory, by Hopkins, 105.

Glaciers, Antiquity of, 109.

Glaciers, Phenomena of, Illustrated, 108.

Glass, Benefits of, to Man, 92.

Glass broken by Sand, 26.

Glyptodon, the, 137.

Gold, Lumps of, in Siberia, 124.

Greenwich Observatory, Chronometers rated at, 229-232.

Grotto del Cane, the, 112.

Gulf-Stream and the Temperature of London, 115.

Gunpowder-Magazines, Danger to, 216.

Gymnotus and the Voltaic Battery, 206.

Gyroscope, Foucault’s, 22.

Hail and Storms, Protection against, 159.

Hail-storm, Terrific, 160.

Hair, Microscopical Examination of, 41.

Harrison’s Prize Chronometers, 229-232.

Heat and Evaporation, 188.

Heat and Mechanical Power, 188.

Heat by Friction, 189.

Heat, Distinctions of, 187.

Heat, Expenditure of, by the Sun, 186.

Heat from Gas-lighting, 189.

Heat from Wood and Ice, 190.

Heat, Intense, Protection from, 191, 192.

Heat, Latent, 187.

Heat of Mines, 188.

Heat, Nice Measurement of, 186.

Heat, Origin of, in our System, 87.

Heat passing through Glass, 189.

Heat, Repulsion by, 191.

Heated Metals, Vibration of, 188.

Heavy Persons, Lifting, 17.

Heights and Distances, to Calculate, 19.

Herschel’s Telescopes at Slough, 95.

Highton’s Minute Battery, 204.

Hippopotamus of Britain, 135.

“Horse Latitudes, the,” 173.

Horse, Three-hoofed, 138.

Hour-glass, Sand in the, 20.

Ice, Heat from, 190.

Ice, Warming with, 190.

Icebergs of the Polar Seas, 180.

Iguanodon, Food of the, 129.

Improvement, Perpetuity of, 5.

Inertia Illustrated, 14.

Jerusalem, Temple of, How protected from Lightning, 167.

Jew’s Harp, Theory of the, 29.

Jupiter’s Satellites, Discovery of, 80.

Kaleidoscope, Sir David Brewster’s, 43.

Kaleidoscope, the, thought to be anticipated, 43.

Kircher’s “Magnetism,” 194.

Leaning Tower, Stability of, 15.

Level, Curious Change of, 144.

Leyden Jar, Origin of the, 216.

Lifting Heavy Persons, 17.

Light, Action of, on Muscular Fibres, 34.

Light, Apparatus for Measuring, 32.

Light from Buttons, 36.

Light, Effect of, on the Magnet, 198.

Light from Fungus, 36.

Light from the Juice of a Plant, 35.

Light, Importance of, 34.

Light, Minuteness of, 34.

Light Nights, 35.

Light, Polarisation of, 33.

Light, Solar and Artificial Compared, 29.

Light, Source of, 29.

Light, Undulatory Scale of, 30.

Light, Velocity of, 31.

Light, Velocity of, Measured by Fizeau, 32.

Light from Quartz, 51.

Lightning-Conductor, Ancient, 167.

Lightning-Conductors, Service of, 166.

Lightning Experiment, Fatal, 214.

Lightning, Photographic Effects of, 45.

Lightning produced by Rain, 166.

Lightning, Sheet, What is it?, 165.

Lightning, Varieties of, 165.

Lightning, Various Effects of, 168.

Log, Invention of the, 173.

London Monument used as an Observatory, 103.

“Maestricht Saurian Fossil,” the, 141.

Magnet, Power of a, 195.

Magnets, Artificial, How made, 195.

Magnetic Clock and Watch, 211.

Magnetic Electricity discovered, 199.

Magnetic Hypotheses, 193.

Magnetic Needle and the Chinese, 194.

Magnetic Poles, North and South, 201.

Magnetic Storms, 202.

“Magnetism,” Kircher’s, 194.

Malachite, How formed, 124.

Mammalia in Secondary Rocks, 130.

Mammoth of the British Isles, 133.

Mammoth, Remains of the, 134.

Mars, the Planet, Is it inhabited?, 82.

Mastodon coexistent with Man, 135.

Matter, Divisibility of, 14.

Maury’s Physical Geography of the Sea, 170.

Mediterranean, Depth of, 176.

Megatherium, Habits of the, 135.

Mercury, the Planet, Temperature of, 82.

Mer de Glace, Flow of the, 110.

Meteoric Stones, no Fossil, 92.

Meteorites, Immense, 91.

Meteorites from the Moon, 89.

Meteors, Vast Shower of, 91.

Microscope, the Eye, Brain, and Hair seen by, 41.

Microscope, Fish-eye, How to make, 40.

Microscope, Invention of the, 39.

Microscope for Mineralogists, 42.

Microscope and the Sea, 42.

Microscopes, Diamond Lenses for, 40.

Microscopes, Leuwenhoeck’s, 40.

Microscopic Writing, 42.

Milky Way, the, Unfathomable, 85.

Mineralogy and Geometry, Union of, 25.

Mirror, Magic, How to make, 43.

Moon’s Attraction, the, 73.

Moon, Has it an Atmosphere?, 69.

Moon, Life in the, 71.

Moon, Light of the, 70.

Moon, Mountains in, 72.

Moon, Measuring the Earth by, 74.

Moon seen through the Rosse Telescope, 72.

Moon, Scenery of, 71.

Moon and Weather, the, 73.

Moonlight, Heat of, 70.

“More Worlds than One,” 56, 57.

Mountain-chains, Elevation of, 107.

Music of the Spheres, 55.

Musket-balls found in Ivory, 237.

Natural and Supernatural, the, 6.

Nautical Almanac, Errors in, 185.

Nebulæ, Distances of, 85.

Nebular Hypothesis, the, 86.

Neptune, the Planet, Discovery of, 83.

Newton, Sir Isaac, his “Apple-tree,” 8.

Newton upon Burnet’s Theory of the Earth, 125.

Newton’s Dog “Diamond,” 8.

Newton’s first Reflecting Telescope, 94.

Newton’s “Principia,” 9.

Newton’s Rooms at Cambridge, 7.

Newton’s Scale of Colours, 49.

Newton’s Soap-bubble Experiments, 49, 50.

New Zealand, Extinct Birds of, 139.

Niagara, the Roar of, 28.

Nineveh, Rock-crystal Lens found at, 39.

Non-conducting Bodies, 215.

Nothing Lost in the Material World, 18.

Objects really of no Colour, 37.

Objects, Visibility of, 30.

Observation, the Art of, 3.

Observatory, Lacaille’s, 101.

Observatory, the London Monument, 103.

Observatory, Shirburn Castle, 101.

Ocean and Air, Depths of unknown, 174.

Ocean Highways, 184.

Ocean, Stability of the, 12.

Ocean, Transparency of the, 171.

“Oldest piece of Wood upon the Earth,” 142.

Optical Effects, Curious, at the Cape, 38.

Optical Instruments, Late Invention of, 100.

Oxford and Cambridge, Science at, 1.

Pascal, How he weighed the Atmosphere, 148.

Pebbles, on, 106.

Pendulum Experiments, 16-22.

Pendulum, the Earth weighed by, 200.

Pendulums, Influence of on each other, 200.

Perpetual Fire, 117.

Petrifaction of Human Bodies, 131.

Phenomena, Mutual Relations of, 4.

Philosophers’ False Estimates, 5.

Phosphorescence of Plants, 35.

Phosphorescence of the Sea, 35.

Photo-galvanic Engraving, 47.

Photograph and Stereoscope, 47.

Photographic effects of Lightning, 45.

Photographic Surveying, 46.

Photographs on the Retina, 236.

Photography, Best Sky for, 45.

Photography, Magic of, 44.

Pisa, Leaning Tower of, 15.

Planetary System, Origin of our, 86.

Planets, Diversities of, 79.

Planetoids, List of the, and their Discoverers, 239.

Plato’s Survey of the Sciences, 2.

Pleiades, the, 77.

Plurality of Worlds, 57.

Polar Ice, Immensity of, 181.

Polar Iceberg, 180.

Polarisation of Light, 33.

Pole, Open Sea at the, 181.

Pole-Star of 4000 years ago, 76.

Profitable Science, 139.

Pterodactyl, the, 130.

Pyramid, Duration of the, 14.

Quartz, Down of, 42.

Rain, All in the World, 155.

Rain, an Inch on the Atlantic, 156.

Rain-Drops, Size of, 154.

Rain, How the North Wind drives it away, 154.

Rain, Philosophy of, 153.

Rainless Districts, 155.

Rain-making Vapour, from South to North, 152.

Rainy Climate, Inordinate, 154.

Red Sea and Mediterranean Levels, 175.

Red Sea, Colour of, 176.

Repulsion of Bodies, 216.

Rhinoceros of Britain, 135.

River-water on the Ocean, 181.

Rose, no Fossil, 142.

Rosse, the Earl of, his “Telescope,” 96-99.

Rotation-Magnetism discovered, 199.

Rotation, the Axis of, 11.

St. Paul’s Cathedral, how protected from Lightning, 167.

Salt, All in the Sea, 179.

Salt Lake of Utah, 113.

Salt, Solvent Action of, 115.

Saltness of the Sea, How to tell, 179.

Sand in the Hour-glass, 20.

Sand of the Sea and Desert, 106.

Saturn’s Ring, Was it known to the Ancients?, 81.

Schwabe, on Sun-Spots, 68.

Science at Oxford and Cambridge, 1.

Science of the Ancient World, 1.

Science, Theoretical, Practical Results of, 4.

Sciences, Plato’s Survey of, 2.

Scientific Treatise, the Earliest English, 5.

Scoresby, Dr., on the Rosse Telescope, 99.

Scratches, Colours of, 36.

Sea, Bottles and Currents at, 172.

Sea, Bottom of, a burial-place, 177.

Sea, Circulation of the, 170.

Sea, Climates of the, 170.

Sea, Deep, Life of the, 174.

Sea, Greatest ascertained Depth of, 175.

Sea, Solitude at, 172.

Sea, Temperature of the, 170.

Sea, Why is it Salt?, 177.

Seas, Primeval, Depth of, 234.

Sea-breezes and Land-breezes illustrated, 150.

Sea-milk, What is it?, 176.

Sea-routes, How shortened, 184.

Sea-shells and Animalcules, Services of, 234.

Sea-shells, Why found at Great Heights, 106.

Sea-water, to imitate, 235.

Sea-water, Properties of, 179.

Serapis, Temple of, Successive Changes in, 111.

Sheep, Geology of the, 138.

Shells, Geometry of, 232.

Shells, Hydraulic Theory of, 233.

Siamese Twins, the, galvanised, 203.

Skin, Dark Colour of the, 63.

Smith, William, the Geologist, 126.

Snow, Absence of in Siberia, 159.

Snow, Impurity of, 158.

Snow Phenomenon, 158.

Snow, Warmth of, in Arctic Latitudes, 158.

Snow-capped Volcano, the, 119.

Snow-crystals observed by the Chinese, 159.

Soap-bubble, Science of the, 48.

Solar Heat, Extreme, 63.

Solar System, Velocity of, 59.

Sound, Figures produced by, 28.

Sound in rarefied Air, 27.

Sounding Sand, 27.

Space, Infinite, 86.

Speed, Varieties of, 17.

Spheres, Music of the, 55.

Spots on the Sun, 67.

Star, Fixed, the nearest, 78.

Stars’ Colour, Change in, 77.

Star’s Light sixteen times that of the Sun, 79.

Stars, Number of, 75.

Stars seen by Daylight, 102.

Stars that have disappeared, 76.

Stars, Why created, 75.

Stereoscope and Photograph, 47.

Stereoscope simplified, 47.

Storm, Impetus of, 164.

Storms, Revolving, 164.

Storms, to tell the Approach of, 163.

Storm-glass, How to make, 164.

Succession of life in Time, 128.

Sun, Actinic Power of, 62.

Sun and Fixed Stars’ Light compared, 64.

Sun and Terrestrial Magnetism, 64.

“Sun Darkened,” 64.