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and pictures must be drawn, and “ Q. How must perspective bè the proportions of the human body studied ? must be studied, in order to learn " A. One must begin by ftudya a good taste of drawing, which the ing a little elementary geometry, master must teach from the pro- and one shall then immediately portions of antique statues; and learn to put all one's figures in perthen the attention must be re- spective. doubled, and the least want of cor- “ Q. A little geometry seems to rectness must not be excused : me insufficient; tince we see that when this is done, and a certain thofe who wish to teach perspective practice of drawing outlines with fundamentally, cause not only the freedom has been acquired, then whole geometry, but also architecthey must begin clare obscute. ture, at least the rules of the five

“ Q. Must the beginner be kept orders, to be learnt, as they affert long in drawing outlines ?

that one cannot lay a thing in due « A. Till he has acquired a perspective if one is not perfectly competent facility:

acquainted with geometry. “ Q. When this is done, what * A. Those who are of that opi. muft he study

nion are not deceived. But I think “ A. He must begin to shade, that to form a painter, the prudent minding to make his drawings with master must endeavour to make the utmost purity; for if he ac- him know all the requisites of his quires then this important quali. art in equal proportions, and not fication; it lasts also afterwards all let him lose his early time, which his lifetime in painting. I shall is the most precious, in things that likewise observe, that when he are not of the first utility. draws in clare obscure he must " Q. Will the painter lose his study anatomy and perspective, in time then, if he studies peripective order to prepare to draw afterwards fundamentally? from life.

“ A. No: but as this is a much " Q. If or drawing geometrical easier thing than others which configures it has been said that fix ftitute the art of painting, it is not months after one can draw well proper that the student should eman academical figure, why must one ploy too much time in it, before {pend one's time in drawing de- learning those which are most nesigns and pictures, since it seems cessary :—the more so, since the arthat it would be more expeditious ticles of perspective which are moft to begin immediately to draw fta- necessary for a painter, are only the tues ?

plan, the square in all its aspects, “ A. It is not so ; for in order the triangle, the round, the oval, to draw statues well, one must know and, above all, to conceive rightly perspective and though I have the difference of the point of view, faid the beginner will in that state and the variety which the point of know how to lay a figure, he must distance produces when taken far not, however, do it; for he would accustom himself to a cold imita. " Q. How is anatomy to be stution, without understanding fore- died? Many say that it is not neShortenings; or he would lose that ceffary, and that those painters who exactness of sight he might have ac- have applied themselves to it, haveall quired.

fallen into a dry and graceless taste.

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to A. Those who say that ana- 6 Q. But anatomy is so long a tomy is not necessary, are grossly study? mistaken; for, without it, it is not «' A. It is certainly not so long possible to reason upon the parts of when rightly taught, that is to say, a naked figure. But in all, mode. when the painter is taught no more ration and judgment must prevail, than what is necessary to him; for there being great difference between a physician and the surgeon must giving all to a part, and knowing study it very differently, as they are how to employ it well; and rules to know all the interior play of the must serve a painter only to uni- parts of man, and the painter wants form himself to nature, and make only to know the effects they have him understand it well.

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PHILOSOPHICAL

PAPERS.

INTERESTING REMARKS, by Dr. Hersche, on the PERMANENTY of

the EQUAL EMISSIONS of Light of our Sun; occasioned by the Changes that have been observed to take place in the LUSTRE of the FIXED STARS.

[Extracted from the first part of the PHILOSOPHICAL TRANSACTIONS of

the ROYAL SOCIETY of LONDON, for the Year 1796.]

Y observations such as this my catalogues. It may suddenly promote and facilitate, we are ena. the back of Cassiopea's chair, and bled to resolve a problem not only the no less remarkable one in the of great consequence, but in which foot of Serpentarius; or gradually we are all immediately concerned. come on like ß geminorum, ß ceti, Who, for instance, would not with 3 sagittarii, and many other into know what degree of perma- creasing stars, for which I also refer nency we ought to ascribe to the to my catalogues. And lastly, it lustre of our sun?. Not only the may turn into a periodical one of stability of our climates, but the 25 days duration, as algol is one of very existence of the whole animal three days, cephei of 5, B lyræ of and vegetable creation itself is in. 6,, antinoi of 7 days, and as many volved in the question. Where others, are of various periods. can we hope to receive information " Now, if by a proper attention upon this subject, but from astro- to this subject, and by frequently nomical observations? If it be comparing the real state of the allowed to admit the fimilarity of heavens with such catalogues of ftars with our fun as a point efta- brightness as mine, it should be blished, how necessary will it be to found that all, or many of the stars take notice of the fate of our neigh- which we now have reason to fu. bouring suns, in order to guefs at fpect to be changeable, are indeed that of our own! That star which subject to an alteration in their among the multitude we have dig- lustre, it will much lessen the connified by the name of sun, to-mor. fidence we have hitherto placed row may flowly begin to undergo upon the permanency of the equal a gradual decay of brightness, like emiffion of light of our fun. Maß leonis, a ccti, a draconis, durfæ ny phænomena in natural history majoris, and many other diminish- seem to point out some past changes ing stars that will be mentioned in in our climates. Perhaps the easiest

way

way of accounting for them may be removed, would be considerably to surmise that our sun has been lessened. Perhaps the thermometer formerly sometimes more and fome. alone night be sufficient. For times less bright than it is at present. though the lustre of the fun should At all events, it will be highly pre- be the chief object of this research, sumptuous to lay any great stress yet, as the effect of light in proupon the stability of the present ducing expanfion in mercury seems order of things, and many hitherto to be intimately connected with the unaccountable varieties that happen quantity of the incident solar rays, in our seasons, fuch as a general it may be admitted that all concluseverity or mildness of uncommon

fons drawn from their action upon winters or burning summers, may the thermometer will apply to the poffibly meet with an easy solution investigation of the brilliancy of the in the real inequality of the sun's fun. And here the forms laid rays.

down by Mr. Mayer, in his little " A method of ascertaining the treatise De Variationibus Thermiqquantity or intenseness of solar metri accuratius definiendis, may be light might be contrived by some of considerable service to distinguish photometer or instrument properly the regular causes of the change of constructed, which ought probably the thermometer from the advento be placed upon some high and titious ones, among which I place insulated mountain, where the in the probable instability of the sun's fluence of various causes that affect luftre." heat and cold, though not entirely

MinerALOGICAL Account of the native Gold lately discovered in IRELAND, in a Letter from ABRAHAM MILLs, Esq. to Sir JOSEPH Banks, Bart. K. B. P. R. S.

[From the same Work.] "TH CHE extraordinary circum- try, I Mall now attempt to describe

stance of native gold being the general appearance, and add found in this vicinity, early excited sucho further information as has my attention, and led me to seize come to my knowledge. the first opportunity that presented " The workings which the itself, after my late arrival here, to peasantry recently undertook are inspect the place where the disco- on the north-eaft side of the mounvery was made,

tain Croughan Kinshelly, within " I went thither on Tuesday, the the barony of Arklow, and county 3d of this month, with Mr. Lloyd, of Wicklow, on the lands of the of Havodynos, and Mr. Weaver. earl of Carysfort, wherein the earl The former having given you some of Ormond claims a right to the account of the circumstances which minerals, in consequence (as I have attended the original discovery, been informed) of a grant in the and, since he left me, a favourable reign of king Henry the Second, day having enabled me to take a by prince John, during his comsecond view of the adjacent coun- mand of his father's forces in Ire

land;

G 3

land; which grant was renewed and bog; the others are formed lowe confirmed by queen Elizabeth, and down the mountain by springs, again by king Charles the Second. which uniting with the former,

“ The summit of the mountain below their junction the gold has is the boundary between the coun- been found. The fmaller have not ties of Wicklow and Wexford; water sufficient to wash away the seven English miles west from Ark- incumbent clay, so as to lay bare low, ten to the south-westward of the substratum; and their beds only Rathdrum, and fix fouth-westerly contain gravel, consisting of quartz from Cronebane mines; by efti- with chlorite, and other subftances mation about six hundred yards of which the mountain consists. above the level of the sea. It ex- The great ravine presents a more tends W. by N. and E. by S. and interesting aspect; the water in its stretches away to the north-east- çlescent has, in a very short distance

ward, to Ballycoage, where shafts from the bog, entirely carried off have formerly been funk, and some the clay, and considerably worn copper and magnetic iron ore has down the substrata of rock, which heen found; and thence to the it has laid open to inspection. N. E. there extends a tract of mine- 4 Descending along the bed of ral country, eight miles in length, the great ravine, whose general running through the lands of Bal- course is to the eastward, a yellow lymurtágh, Ballygahan, Tigrony, argillaceous Aristus is firů seen; the Cronebane, Connery, and Kilma- laminæ are much shattered, are very coe, in all which veins of copper thin, have a light hade to the ore are found; and terminating at S.S.W. and range E.S.E. and the fate quarry at Balnabarny. W.N.W. Included within the

" On the highest part of the fift, is a vein of compact barren mountain are bare rocks, being a quartz, about three feet wide, variety of argillite, whose joints ranging N.E. and S.W.; below range N.N.E. and S.S.W. hade to this

is another vein, about nine inchthe S.S.W. and in one part include es wide, having the same range a rib of quartz, three inches wide, as the former, and hading to the which follows the direction of the northward, confisting of quartz, dtrata. Around the rocks, for fome including ferruginous earth. Lower distance, is found ground, covered down, is a vein of a compact aggrewith heath; descending to the east- gate substance, apparently comward, there is springy ground, pounded of quartz, ochraceous abounding with coarse grais; and earth, chert, ininute particles of below that, a very extensive bog, miva, and some little argillite, of in which the turf is from four to unknown breadth, ranging E. and nine feet thick, and beneath it, in W. hading fast to the southward, the substratum' of clay, are many and including strings of quartz, angular fragments of quartz, con- from one to two inches thick, the taining chlorite, and 'ferruginous quartz containing ferruginous earth. earth. Below the turbary the ground The yellow argiilaceous fhriftus is falls with a quick defcent, and three again seen with its former hade and ravines are observed. The central range; and then, adjacent to a quartz one, which is the moit conside- vein, is laminated blive argillaceous rable, has been worn by torrents, Thistus, ranging N.E. and S.W. which derive their source from the and hading S.Ě.; which is after

wards

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