«8 



Proceedings of Learned Societies, 



[Jan 



that neither water, ether, alcohol, nor the 

 alkahne sub-carbonates, have any effect on 

 this colour, which is green. Caustic i)Ot- 

 a?h turns it sky-blue, soda does not alter 

 it at all ; and no acid, with the exception of 

 the sulphuric oxalic, destroys the colour 

 entirely. By dissolving this substance in 

 acetic acid, a green tint is obtained the 

 -beauty of which is still greater. 



To obtain the true ellipticity of the earth 

 has long been a scientific desideratum : it 

 is a problem which, during the whole of 

 the last century, occupied the attention of 

 every mathematician and philosopher. 

 Newton had estimated it at -^^q; La Place, 

 by applying his profound calculus to the 

 lunar motions, was led to conceive it soi st- 

 Each new measure of a degree on the 

 earth's surface afforded a different result. 

 Clairaut had given a formula, by which the 

 ellipticity of the earth was connected with 

 the centrifugal force at the equator ; and as 

 the latter can be determined by means of 

 the pendulum, the latter may be readily 

 deduced — to ascertam the force of gravity 

 at the equator, and its total diminution from 

 the pole to the equator, by observing the 

 time in which a given pendulum oscillates 

 in different latitudes, and thus to obtain 

 the numerical value of certain terms in 

 Clairaut's formula, has been the object of 



Captain Sabine in his recent voyage. From 

 son:e thousands of observations made be- 

 tween the latitudes of 13*^ south and 80° 

 north latitude, he deduces, by calculation, 

 that the ellipticity of the earth is ^,V % ^^ 

 the equatorial diameter : this, however, can 

 only be considered as a good approxima- 

 tion, to be hereafter modified when obser- 

 vations on the pendulum shall have been 

 made under these circumstances : — the 

 difference between Sir Isaac Newcon and 

 Captain Sabine is tV* It, between Cap- 

 tain S. and La Place is^^^-?^' y^^ 



A chronometer, the principle of which 

 consists hi the continual disi)lacement of 

 the centre of gravity of the arm of a lever, 

 has excited much interest in France. This 

 lever has the form of an arrow, \\hich is 

 capable of moving round a horizontal axis 

 fixed in the middle of a dial-plate divided 

 into twelve hours. This ingenious machine 

 has been ascribed by his countrymen to M. 

 Lenormand; it had previously been con- 

 structed in this country by an excellent ma- 

 thematical instrument maker, Mr. Schnial- 

 calder, who, with the modesty and candour 

 of real merit, did not palm u|)on the world, 

 as of his own invention, a piece of mecha- 

 nism, of which we believe him to have been 

 the first constructor, but which is described 

 in several old works upon mechanics. 



PROCEEDINGS OF LEARNED SOCIETIES. 



DOMESTIC. 

 ROYAL SOCIETY. 



The meetings of this society were re- 

 sumed on the 17th Noveniber, when a 

 paper was read, " On the Changes that 

 have taken place in some ancient Alloys of 

 Copper," by John Da\-y, m.d., f.r.s.; and 

 another, containing " Observations on the 

 apparent Positions and Distances of 4-68 

 doable and triple fixed Stars, made at tlie 

 Observatory at Passy, near Paris, in the 

 summer of 1825," by James South, f.r.s. 

 On the 2'ith a paper was read, " On the 

 Comparison and Adjustment of the new 

 Weights and Measures," by Ca])t. Kater, 

 r.R.s. On the 30th the society met for the 

 choice of officers for the ensuing year ; when 

 John Barrow, Esq., John Bostock, M.D., 

 Sir Astley Pziston Cooper, Bart., Benjamin 

 Gompertz, Esq., Sir Abraliam Hume,Bart., 

 Daniel Moore, Esq., Richa:d Earl of Mount 

 Edgecombe, Peter Mark Roget, m.d., and 

 James South, Esq., formed the list of the 

 new council. 



At the anniversary dinner of the society, 

 Mr. Peel announced that his Majesty had 

 placed two annual medals, of the value of 

 fifty guineas each, at the disposal of the 

 council of the Royal Society, to be distri- 

 buted by them as rewards for scientific dis- 

 coveries. I'iie tvro Copley medals were 

 awarded to M. Arrago, the Astronomer- 



Royal of France, and to Mr. Barlow, the 

 Professor of Mathematics in the Military 

 Academy at Woolwich. Both these me- 

 dals were gi\en for discoveries relating to 

 the variation of the magnetic needle. 



BOYAL ACADEMY. 



At the annual distribution of premiums 

 which took place on the 7th December, 

 the following students received prizes for 

 their performances. 



Mr. Wood, the gold medal and the Dis- 

 courses of Reynolds and West, for an his- 

 torical painting, representing Joseph ex- 

 pounding the dreams of Pharaoh's chief 

 butler and baker. Mr. Deare, the gold 

 medal, with the same Discourses, fot a mo- 

 del of the death of Goliah, an astonishing 

 performance for a young man, abounding in 

 grace, vigour, and propriety of adtion. Mr. 

 Bassett, the gold medal and the same, for 

 a design for a national edifice adapted for 

 the Royal Academy, the Royal Society, 

 and the Society of Antiquarians. Mr. 

 Webster, a silver medal, with the Lectures 

 of Barry, Opie, and Fuseli, for the best co- 

 py of a " Virgin and Child," by Vandyke — 

 a performance which proves that this young 

 artist has appreciated all the peculiar me- 

 rits of his attractive original. Mr. Fan. 

 comt, a silver medal for the second best 

 copy. Mr. Wood, a silver medal, with 



