the calorific Powers of the different prismatic Rays. 405 



Humphry Davy, &c. &c. and more lately those of Malus, Biot, 

 Leslie, Brewster, &c. &c. 



The work in which those experiments are printed was pub- 

 lished in octavo, at Paris, in 1783; and is entitled Recueil de 

 Mtmoires siir la Mccaniqiie et la Physique. It contains several 

 other memoirs on heat, light, optical instruments, mechanics, 

 and engraving: the principal of them are as follows: 



On a new micrometer made of rock crystal, and additions to 

 ditto. 



On the means of employing the double refraction of rock cry- 

 stal for the precise measurement of small angles ; determination 

 of the diameters of the planets by this method ; with a brief de- 

 scription of an instrument intended to measure with accuracy 

 the moon's angular distance from the stars, when this distance 

 does not exceed twenty degrees. Continuation of the preceding 

 researches. 



A certificate and statement of the prior claim which the Abbe 

 Rochou had to the invention of the prismatic micrometer in pre- 

 ference to the Abbe Boscovich, signed by Borda, Bezout,'Van- 

 dermonde, and Cassini. 



A table, serviirg to determine angles which result from tWo 

 prisms laid one on the other. 



An essay on the measurement of angles, bv means of prisms of- 

 rock crystal and of glass : determination of the diameters of the 

 planets by these methods ; and diiferent inquiries, which prin- 

 cipally concern the analysis of colours and achromatic tele- 

 scopes. 



Inquiries respecting the nature of the light of the fixed stars. 



On glasses having spherical surfaces ; their aberration ; lenses 

 of spirit of wine, and otlier kinds of Piuids, by wiiich the effects 

 of the internal surfaces of glasses are considerably diminished. 



Account given of the examination of these glasses, by Borda, 

 Le Gentil, and Cassini the younger. 



On vision ; and the result of the examination of his experi- 

 ments on this subject, and other questions relating to. the func- 

 tions of this organ, by Bezout, Bory, and Borda. 



Of the optical diasporameter, an instrument for measuring the 

 dispersion of colours. 



On the means of rendering M. Bouguer's heliometer capable 

 of measuring angles of a considerable size, in order to facilitate 

 the oi)servations of distances of stars from the moon. 



Descri])tion of a method of rendering Hadlcy's qnadrant sus- 

 ceptible of measuring all angles, from degrees to 180 degrees. 



Report of Messrs. Lemonnier, Le Roy, and Coudorcet, on two 

 microineters invented by the Abbt' Rochon. 



C c 3 Memoir 



