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of its length and height, with all those in the intermediate fituations projected into a great circle. This exactly agrees with the appearance of the milky-way, and Mr. Herschel thinks it highly probable that the sun is in the famie ftratum. But, if a smaller firatum intersect the great one, the eye, at no great distance from the point of intersection, will see the smaller stratum as a lucid branch; so that it is probable this great ftratum is intersected by another, and that our sun is in a part of it not far distant from the point of intersection. This is confirmed by what our author calls a star-gage; for he, who talks of col. lecting bundles of itars of two or three hundred at a time, and offering them to the Royal Society,' may be allowed to afsume the rule, and gage the heavens. In the parallel from 92° to 94' north polar dittance, and 15h 10' right afcenfion, the ftar-gage runs up
from stars in a field of view to 18.6. But in the parallel from 780 to 80°, and right ascension 11, 12, 13, and 14", from 3.1 it feldom rises above 4. We just now observed, that, in this stratum, those stars which are in the di. rection of the length and height of the plane, with those in the intermediate situations, appear in the form of a great circle ; those in the direction of its fides necessarily appear to be scattered without any particular arrangement. From this it seems to follow, that the milky-way, and the diftin& stars of different magnitudes belong to the stratum, or perhaps more properly speaking, the groupe to which the fun belongs. We are by no means clear respecting Mr. Herschel's opinion of the other trata ; in one passage he seems to consider each nebula as a distinct stratum.
• If the eye were placed somewhere without the fratum, at no very great distance, the appearance of the stars within it would assume the form of one of the less circles of the sphere, which would be more or less contracted to the distance of the eye ; and if this dittance were exceedingly increased, the whole ftratum might at last be drawn together into a lucid spot of any thape, according to the position, length and height of the Atratom.'
In another passage, he is rather inclined to think the strata formed of groupes of nebulæ ; and this seems by inuch the most probablc opinion.
* A very remarkable circumstance, attending the nebulæ and clusters of fears is, that they are arranged into ftrata, which seem to run on to a great length; and some of them I have al. ready been able to pursue, so as to guess pretty well at their form and direction. It is probable enough, that they may furround the whole apparent sphere of the heavens, not unlike the milky-way, which undoubtedly is nothing but a stratum of C2
fixed stars. And as this latter'immense starry bed is not of equal breadth or luftre in every part, nor runs on in one straight direction, but is curved and even divided into two streams along a very considerable portion of it; we may likewise expect the greateit variety in the strata of the clusters of itars and nebulæ. One of these nebulous beds is so rich, that, in palling through a section of it, in the time of only thirty-six minutes, I detected no less than thirty-one nebulæ, all distinctly visible upon a fine blue sky. Their situation and shape, as well as condition, seem to denote the greateit variety imaginable. In another stratum, or perhaps a different branch of the former, I have seen double and treble nebulæ, variously arranged ; large ones with small, seemingly attendants; narrow but much extended, lucid nebulæ or bright dashes ; some of the shape of a fan, resembling an electric brush, issuing from a lucid point; others of the cometic shape, with a seeming nucleus in the cen. ter; or like cloudy stars, furrounded with a nebulous atmos. phere ; a different fort again contain a nebulosity of the milky kind, like that wonderful, inexplicable phenomenon about 6 Orionis; while others shine with a fainter, mottled kind of light, which denotes their being resolvable into stars.'
There are many other curious particulars in this paper, but we have already extended our account of it far enough.
Art. XXXIV. An Account of a new Species of the BarkTree, found in the Inand of St. Lucia. By Mr. George Da vidson,-- In the fixty-seventh volume of the Philosophical Transactions, p. 504., we received an account of a species of cincona, found in Jamaica. This seems very much to resemble it, so far as we perceive from the imperfect description in that volume ; and both are varieties of the Cincona Caribbæa of Linnæas, in the last edition of the Species Plantarum. Its properties we had occasion to describe in our review of Dr. Kentilh’s pamphlet, vol. lix. p. 15.
Art. XXXV. An Account of an Observation of the Mea teor of August 18, 1783, made on Hewit Common, near York. By Nathaniel Pigott, Esq. F.R.S.-This is the same meteor observed by Messrs. Cavallo, Aubert, Cooper, and Blagden, of which we have already given a full account.
Art. XXXVI. Observations of the Comet of 1783. By.' Edward Pigott, Esq.—This comet was observed the 19th of November, 1783. It had exactly the appearance of a nebula, and its light was very faint. Mr. Mechain, at Paris, discovered it the 26th of November, fever days after Mr. Pigott's first obfervation.
Art. XXXVII. Experiments on mixing Gold with Tin. By Mr. Staneiby Alchorne, of his Majesty's Mint.--Dr. Lewis had observed that the smallest proportion of tin and lead, or
even their vapours, though they did not add weight enough to the gold, to be fenfible in the tenderest ballance, rendered it so brittle, that it flies in pieces under the hammer. Mr. Alchorne has examined this subject by experiment, and found that even one twenty-fourth part of tin did no very essential injury to the malleability of gold, and the fumes had no effect. The mixtures grew more hard and hars, in propora tion to the quantity of alloy; but not one of them had the appearance of what workmen call brittle gold. Mr. Alchorne therefore thinks, with great reason, that the brittleness arose from the impurity of the tin. Twelve grains of regulus of arsenic will destroy the malleability of as many ounces of gold.
Art. XXXVIII. Sur un moyen de donner le Direction aux Machines Aëroftratiques. Par M. Le Comte De Galvez.
-On the Means of directing Areostatic Machines. By the Count of Galvez.- The count of Galvez having communi. cated to us his ideas on the means of directing areoftatic machines at pleasure, by a certain rhumb-line in the air, founded on different observations on the use which birds make of their wings in Aying, and fishes of their fins and tail when they swim,- We the undersigned certify' - What? that we failed on the canal of Manzanares in a boat with very little wind, by the help of moveable fails like wings. Adieu Messrs, and, in return for your laborious certificate, and the very accurate plate which accompanies it,-may you receive a fuperior portion of discernment, and a little more philoso. phical accuracy!
Art. XXXIX. An extraordinary Case of a Dropsy of the Ovarium, with some Remarks. By Mr. Philip Meadows Martineau, Surgeon.—The quantity of water drawn from this poor woman was greater than that related to have been taken from lady Page. The whole was fix thousand fix hundred and thirty-one pints, or upwards of thirteen hogsheads. On an average, she might collect about two-thirds of a pint each day, and sometimes probably between two and three pints. She lived, in this state, twenty-five years, and was tapped 80 times. On dissection, all the parts were much thickened by the pressure ; but generally sound, except the left ovarium, which was the original seat of the disease, and was enlarged into an immense pouch.'
Art. XL. Methodus inveniendi Lineas Curves ex proprietatibus Variationis Curvaturæ. Pars secunda. Auctore Ni. colas Landerbeck, Marthes. Profetr. in Acad. Upsaliensi. -This is the second part of the author's Method of find
ing Curves, from the Properties of the Variation of Curva ture, The former was inserted in the last volume of the Transactions, and we mentioned it in volume fifty-eight, page 339: it is incapable of abridgement.
The volume is, as usual, concluded with the list of presents and the names of donors; but these afford no subject of remark
Planting and Ornamental Gardening; a practical Treatise. Svo
85. in Boards. Dodsley. WE
E cannot agree with this intelligent author, in thinking,
that the two arts, which are the subjects of his work, are so ultimately connected“ as to become an unity.' That plantations are a part of those ornaments, which modern taste has admitted into gardens may be allowed, and consequently that they are nearly allied; but, in this way, one part of the subject of planting, viz. the disposal of the various trees, is only the object of the ornamental gardener. There are many others very remotely connected with it. This is not the only part where our author has expressed himself inaccurately, probably from not being accustomed to composition. There are many professed book-makers in the metropolis, who would have avoided those errors ; but they would have been unable to entertain and instruct their readers with a volume so full of useful information. “Man,' he says, ' must be employed; and how more agreeably than in conversing with nature, and seeing the works of his own hands, afifted by her, rising into perfeciion.' In this sentence, we suspect the works to be those of nature, and the asistance that of art. There are fonie other inaccuracies of this kind; but they are venial ones, and the merit of the work is considerable enough to obscure them.
The introductory discourses contain the elements of planting, viz. concise directions for propagating, in the various ways usually employed, planting, training, and transplanting. These are new and judicious. The outline of the Linnæan fyftem, taken from the English translation, follows; and we entirely agree with the author in thinking, that if Linnæus had founded his distinction of the classes and orders on the an. thera and pistils, as parts of the flower, and not as sexual organs, he would have ' saved himself from a host of enemies.' We do not perceive how he would have rendered his • system infinitely more fimple and scientific, and consequently more useful than it really is.' The same distinctions would have remained, though under different titles; not to add, thạt the distinction of the orders of the class fyngeneha, are better re
membered when once learned in this (perhaps fanciful) language, than they probably would have been in a more floral system.
The vegetables employed in planting and ornamental gar. dening are next arranged in an alphabetical order. The au. thor tells us, and, on examination, we find bis information juft, that, fo far as it relates to timber trees and other native plants, as well as to some of the more useful exotics, the remarks are either his own, or contain such additions as have resulted from his own observation and experience. The description and management of ornamental exotics is, in substance, taken from Hanbury, with some additions from other authors.
After this extended catalogue, the rest of the subject is explained in detached articles. Those on timber, hedges, and woodlands, are new and valuable. Those on grounds are new in form; the substance is sometimes taken from Wheatly and Mason, and their ideas are often corrected and limited by a careful examination of the effects, from actual observation. In this part the author displays a correct and cultivated taste.
In the catalogue of plants, the author, under each genus, describes the different species, with their uses, and the method of propagating them. There are various passages which have excited our attention ; but we shall select the following account of the Tortworth chestnut-tree, to correct a very general er
• The larget (chestnut tree) we know of in this country stands at Tortworth, near Berkley, in Gloucestershire. Sir Robert Atkins, in his History of Glouceftershire, says, “ By tradition, this tree was growing in king John's reign ;” and Mr. Marsham calculates it to be “ not less than eleven hundred years old.” Sir Robert makes it nineteen yards, and Mr. Marsham forty-six feet fix inches in circumference. With great deference however to the authority and veracity of these gentlemen, we have every reason to believe that what is called the Tortworth chestnut is not one, but two trees : supposing them to be only one, its dimenfions are by no means equal to what are given above. We have the highest opinion of Mr. Martham's ingenuousness and accuracy; and fortunately, in this cafe, he has furnished us with a proof of his candour, in faying, “ As I took the measure in a heavy rain, and did not measure the string till after I returned to the inn, I cannot so well an. fwer for this as the other measures." We will venture to add, that had the day been fine, and Mr. Marsham had viewed the field fide as well as the garden side of this venerable tuin; had he climbed upon the wall, and seen the gable of the old building, adjoining, clasped in between the two items; and had further ascended to the top of the old stump, which is not more