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ward of De la Goa Bay, six miles west of the city Mashow, and above 1000 miles in nearly a straight direction from the Cape of Good Hope.

"The country from whence this rhinoceros comes, contains no thick woods, or forests, but is covered with separate clumps of trees, like a nobleman's park in England. In travelling, you always appear to be approaching a wood; but as you advance, the trees are discovered to stand at a distance from one another, or rather in little clumps.

"This animal feeds upon grass and bushes; is not carnivorous, and not gregarious; seldom more than a pair are seen together, or in the vicinity of one another. Mr. Campbell's people wounded another of the same description. When enraged it runs in a direct line, ploughing the ground with its horn. The hide is not welted, is of a dark brown colour, smooth, and without hair."

Sir Everard then proceeds to describe the skull, and especially to point out its exact resemblance to the fossil skull from Siberia, whence he concludes "That although many animals belonging to former ages may be extinct, they are not necessarily so; no change having taken place in our globe, which had destroyed all existing animals, and therefore many of them may be actually in being, although we have not been able to discover them."

Our author then adverts to the immense tracts of Africa which remain unexplored, and to the probability that they form the retiring places of animals not disposed to submit to the will of man; he quotes the following document to show in what way particular animals may elude our inquiry at one time, and at another be brought

within our reach.

"Mr. Campbell says, he found that the wild ass, or quagga, migrates in winter from the tropics, to the vicinity of the Malaleveen river, which though farther to the south, is reported to be warmer than within the tropic of Capricorn, when the sun has retired to the northern hemisphere. He saw bands of two or three hundred, all travelling south, when on his return from the vicinity of the tropic; and various Bushmen, as he proceeded south, inquired if the quaggas were coming. Their stay lasts from two to three months, which in that part of Africa is called the Bushmen's harvest. The lions who follow them are the chief butchers. During that season, the first thing a Bushman does on awaking, is to look to the heavens to discover vultures hovering at an immense height; under any of them he is sure to find a quagga that had been slain by a lion in the night."

The author then goes on to draw a comparison between the docility of the elephant, the horse, and the rhinoceros, and refers the untameableness of the latter to the smallness of its brain; he concludes his paper as follows:

"The following account of the manners and habits of the Asiatic rhinoceros, clothed in armour, and having the welted hide, I have taken from the young man who was its keeper for three years in the Menagerie at Exeter Change, at the end of which period it died.

"It was so savage that, about a month after it came to Exeter Change, it endeavoured to kill the keeper, and nearly succeeded. It ran at him with the greatest impetuosity, but fortunately the horn passed between his thighs, and threw the keeper on his head; the horn came against a wooden partition, into which the animal had

forced it to such a depth, as to be unable for a minute to withdraw it, and during this interval the man escaped.

" Its skin, although apparently so hard, is only covered with small scales, of the thickness of paper, with the appearance of tortoise shell; at the edges of these, the skin itself is exceedingly sensible, either to the bite of a fly, or the lash of a whip; and the only mode of managing it at all was by means of a short whip. By this discipline the keeper got the management of it, and the animal was brought to know him: but frequently, more especially in the middle of the night, fits of phrenzy came on, and while these lasted nothing could control its rage, the rhinoceros running with great swiftness round the den, playing all kinds of antics, making hideous noises, knocking every thing to pieces, disturbing the whole neighbourhood, then all at once becoming quiet. While the fit was on, even the keeper durst not make his approach. The animal fell upon its knees to enable the horn to bear upon any object. It was quick in all its motions; ate ravenously all kinds of vegetables, appearing to have no selection. They fed it on branches of the willow. It possessed little or no memory, dunged in one place, and, if not prevented, ate the dung, or spread it over the sides of the wall. Three years' confinement made no alteration in its habits.

“ The account in the Bible of an unicorn not to be tamed, mentioned by Job, bears so great an affinity to this animal, that there is much reason to believe that it is the same, more especially, as no other animal has ever been described so devoid of intellect. In that age, the short horn might readily be overlooked, as it cannot be considered as an offensive weapon, and the smoothness of the animal's skin would give a greater resemblance to the horse than to any other animal.

On the Electric Phenomena exhibited in Vacuo. By Sir Humphry

Davy, Bart., P.R.S. Is electricity a subtile fluid, or are its effects merely the exhibition of the attractive powers of the particles of bodies ? Are heat and light elements of electricity, or mere effects of its actions? Is magnetism identical with electricity, or an independent agent, put into motion or activity by electricity? Though these abstruse and difficult questions exceed our present means of solution, it appeared to Sir Humphry an object of considerable moment, and intimately connected with them, to determine the relations of electricity to space as nearly void of matter as it can be made upon the surface of the earth; his experiments on these subjects are detailed in this paper.

The most perfect mercurial vacuum that could be procured was permeable to, and rendered luminous by, electricity; when the tube was very hot the light was green and dense; as the temperature diminished it became less vivid, and at - 20° was scarcely perceptible,

except in a very dark place. The ingress of very small portions of air rendered the light blue and purple, and increased the conducting power of the medium. In a vacuum above fused tin, the phenomena was nearly the same. From the general results of these experiments, it is inferred “that the light and probably the heat,) generated in electrical discharges, depends principally upon some properties or substances belonging to the ponderable matter through which it

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passes; but they prove likewise that space, where there is no appreciable quantity of this matter, is capable of exhibiting electrical phenomena; and, under this point of view, they are favourable to the idea of the phenomena of electricity being produced by highly subtile fluid or fluids, of which the particles are repulsive, with respect to each other, and attractive of the particles of other matter. On such an abstruse question, however, there can be no demonstrative evidence."

This paper contains many valuable hints respecting the existence of air in mercury, and the best means of obtaining a vacuum free from it, which seem of considerable importance in their relation to the construction of barometers.

M. M. Gay Lussac and Welter are occupied at present with the heat disengaged by the gases, when their volume is made to vary under very different pressures. They have already obtained several results, which they propose to submit to the Academy of Sciences, when their labour shall be more complete; but meanwhile they have thought it right to communicate a fact which appears to them very singular.

It is known that when we dilate air, or any other elastic fluid, by enlarging the space in which it is enclosed, cold is produced. The fact observed by these gentlemen is announced in the following proposition : " The air which escapes from a vessel in blowing through an aperture, under any pressure whatever, does not change the temperature, although the air is dilated in issuing from the vessel.”

It would seem to result from this, that there is heat produced in the blowing of the air, and that this heat is as much more considerable as the difference of pressure which produces the blast is greater; so that the heating compensates exactly the cold produced by the dilatation. This fact would explain why heat is produced when air enters into a void space, or one occupied by air at a smaller pressure. It would explain also why the blast of the machine with the column of water at Schemnitz produces cold and congeals water; whilst the blast of the reservoir of air of the steam-engine at Caillot, where the pressure is constant, and of 2.6 atmospheres, does not affect the thermometer.

Description of a Ductilimetre, or an Instrument for comparing the Ductility of different kinds of Lead, Tin, &c., described in the Annales des Mines, tom. vii.- This instrument is the contrivance of M. Regnier, and is said to furnish an useful means of trying different samples of lead and tin, more especially with a view of judging of their fitness for lamination. It consists of a mass of iron of a given weight, attached to the extremity of an iron lever, thirty inches long. Ľhe other end of this lever is moveable upon a transverse axis. When the hammer is elevated to a certain angle which may be measured upon the quadrant of ninety degrees, it may be let fall upon the steel anvil which is attached to the small table upon which the whole is fixed.

In using this instrument, the different kinds of lead are cast into bullets of twenty-six to the pound, having a diameter of four-tenths of an inch; these are carefully smoothed and placed in the centre of the

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anvil, upon the surface of which are engraved several concentric circles; the hammer is then elevated to 50°, and let fall upon the ball under examination, which becomes flattened by the successive blows into a disc of 1.2 inches diameter. The number of blows given to each ball, in order to produce this extension, are counted. The following table shows the results of some of these trials: Samples.

Number of Blows.
1 Old sheet lead
2 New lead in pigs (W. Blackett)
3 Ditto
(Blangill)

11
4 Ditto
(Caldebek)

12
5 New sheet lead

12 6 Old lead of ten fusions

10 7 Cuttings of lead

12 8 Lead, with one-tenth of zinc

14 9 Tin

40 It appears that lead, ten times remelted, instead of being injured, is improved in quality; that lead mixed with one-tenth of zinc is very sensibly hardened, and that the hardness of the best English tin is to that of the softest lead as four to one.

Strength of Cast Iron.—The increasing use of cast iron as a substitute for wood in building, has lately drawn considerable attention to the various circumstances affecting its strength and durability. Upon these subjects some interesting and important facts will be found in Mr. Tredgold's practical essay upon the above subject. We may daily observe among the new buildings of the metropolis, entire houses which are stilted, as it were, upon iron columns, with a view of gaining space upon the ground floor; and in many large buildings, the beams and roofs are entirely of iron, to the complete exclusion of all timber; it gives safety against fire, is not liable to sudden decay, nor soon destroyed by wear and tear; and it can be easily moulded into the form of greatest strength, or that best adapted for the intend ed purpose. It must, however, be remembered, that iron varies extremely in quality; that the method of casting materially affects its strength; and that this is also greatly dependent upon many minute circumstances, which in ordinary cases are not attended to: such, for instance, as the exclusion of air-bubbles; the temperature of the moulds; and above all, the time allowed for cooling, which, when performed very slowly, affords a much tougher material than when effected too rapidly. This annealing of cast iron, we believe, is frequently neglected, and we can speak from experience of its high importance. The best test of the quality of a piece of cast iron is to strike the edge with a hammer; if it make a slight impression, denoting some degree of malleability, the iron is of a good quality; but if fragments fly off, without any sensible indentation, the iron will be hard, brittle, and not to be relied on. It must, however, be remembered, 11.* large beam of iron, different parts will often have differer + depending generally upon their situation in the mould. mend Mr. I'redgold's book, as calling the attention of to these and several other important subjects, whic! to leave to the honesty or care of the iron-foun

every architect, engineer, and builder ought to be able to judge for himself.

Steam Engine Chimneys.

To the Editor of the Journal of Science, &c.

Sir, In a former number of your Journal, (No. 24, p. 352,) a suggestion is thrown out, that chimneys, in other respects equal, emit smoke in quantities greater or less in proportion to their height.

The object of this communication is to furnish you with a more direct illustration of the truth of that remark, than either of the examples cited in the Journal affords.

In passing through the town of Durham in the winter of 1815, my attention was attracted by a chimney of unusual height, situated at some distance from the town, and on the opposite bank of the river. Upon inquiry, I learned that this chimney belonged to a steam-engine, employed in a coal mine, and that it had been erected some years before, under the following circumstances:

The engine had formerly been provided with a chimney of the ordinary kind, from which such volumes of black smoke were discharged, as to render it, when the wind blew in a particular direction, an intolerable nuisance to the town.

When, therefore, the lease expired of the ground upon which the engine was erected, the Dean and Chapter (to whom the ground belonged,) refused to renew it except upon the condition, that a chimney should be erected so high as to carry the smoke completely clear of the town. The condition was acceded to; and a chimney was in consequence built, the summit of which was elevated upwards of one hundred feet above the fireplace. The experiment was completely successful, but not exactly in the manner which had been contemplated; for the town was relieved, not so much by the smoke being carried to a greater elevation than formerly, as by the change which was produced in the quantity and quality of that actually emitted.

Nor had the proprietors any reason to regret the expense to which they had been put in erecting the new chimney; for the quantity of coal consumed by the engine was (as my informant stated) much less than formerly, and the consumption was so perfect, as to render all cleansing of the flue unnecessary.

As the preceding account was received on the spot, and from a person employed in the works, it may, I believe, be considered as in general accurate; but as I cannot vouch for that accuracy from personal experience, I beg leave to suggest the propriety of inviting some inhabitant of Durham to corroborate or to correct the statements it contains.

M.

The smoke-burning schemes have all ended in smoke, as we ventured to anticipate would be the case in the article to which our correspondent M. alludes. There can be no doubt that no large engine in the metropolis, or near houses to which it can prove a nuisance, should be suffered to be erected without a chimney at least one hundred feet in height from the ground.

The Manufacture of Wine improved by Chalk.-Count Alexander Czacki, after an experience of four years, recommends the addition

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