-299 



CATALOGUE. — PHYSICAL OPTICS, 



"Wilson on flattening the cross wires of tele- 

 scopes. Ph. tr. 1774. 105. 

 Boscovich's micrometer. Ph.tr. 1777. 789. 



A prism of glass, or of rock crystal, divided by a spherical 

 surface, and moveable also along the axis of the telescope. 



Ramsden on two new micrometers. Ph. tr. 



1779.419. 



Finds the divided object glass insufficient. The first 

 method is to divide the small speculum of a telescope of 

 Cassegrain's construction, and to give it a motion round a 

 point near the centre : the second is to divide the eyeglass. 

 The aberration of the telescopes of Cassegrain is about | of 

 the aberratien of the Gregorian telescopes : the error of the 

 eyeglass has much less effect than that of the object glass 

 employed as a micrometer ; the divided glass is placed in 

 the focus of that lens in the eyepiece, which is nearest to 

 the object glass. 



Herschel's lamp micrometer. Ph. tr. 1782. 

 Herschel's improvement of his angulfir mi- 

 crometer. Ph. tr. 1785.46. 

 Smeaton's equatorial micrometer. Ph. tr. 



1787. 

 Rochon on telescopes with micrometers of 



rock crystal. N. A. Petr. 1788. VI. H. 37. 



Nich. 8. IV. no. 

 Rochon's prismatic micrometer. Recueil de 



mec. 

 Rochon's achromatic micrometer. Journ. 



Phys. LIII. 169. 

 Kdstner on micrometers. Astronomische ab- 



handl. II. 263. 

 Kastner on terrestrial micrometers. Com- 



mentat. Gott. I7S9. X. M. 1. 

 Cavallo on a micrometer. Ph. tr. I79I. 283. 



Made of semitransparent mother of pearl. A table for 

 e*imating distances from apparent magnitudes of a man. 

 Perhaps the bricks of a house would afTord a more certain 

 measure. 



Cavallo on a micrometer. 4. Lond. 1793. 



*£nc. Br. Art. Micrometer. 



Rand's patent military telescope. Repert. 



XII. 152. 



With a micrometer and a table. 



Physical Optics. 



Sources of Li"ht. 

 LoOTOwojorc' de origine lucis. 4. Petersb. 175f*. 



Light from Combustion. 



Boyle's lamp. Hooke Ph. Coll. n. 2. 



Hooke's lamp. Birch. II. 155. 



Hooke's lampas. Lect. Cutl. 



A lamp with water dropping in. Ph. tr. IC93. 



XX. 378. 

 Bouguer's comparison of the light of the sun 



and moon with the light of candles. A. P. 



172G. H. 11. 



Confirmed by Celsius, in (be ratio of 300000 to i. 



Virgile's subaqueous lantern. Mach. A. VI. 



77. 

 Bourgeois de Chateaublanc's reflecting lamp. 



A. P. 1744. H. 62. 

 Preigney's lamp of Amiens. Mach. A. VII. 



395. 

 Lievreville's reflecting lamps. A. P. 1759, 



H. 234. 

 Fordyce on light from inflammation. Ph. tr. 



1776.504. Roz. XIII. Suppl. 115. 



Thinks that all light arising from decomposition is blue, 

 and attributes other colours to ignition. 



A night lamp. Roz. XI. 56. 

 On lighting theatres. A. P. 1781. 409. 

 Morgan on the light of bodies in combus- 

 tion. Ph. tr. 1785. 190. 



Thinks that the more refrangible rays are always first thrown 

 off in combustion ; but that they are often extinguished by 

 the surrounding vapour, so that the flame may thus become 

 even at first yellow, green, or even red. Melted brass exhir 

 -bits a fine green vapour. Rotten wood burning exhibits 

 only the orange and red rays. 



Villiers's lamp for reading at night. Roz 

 XXVIII. 54. 



