284 



CATALOGUE. — OPTICAL INSTRUMENTS. 



Compares the focal image formed by oblique rayj to the 

 profile of Saturn with his ring. 



Lahire on centering lenses. A. P. 1699. 139. 



H. 86. 

 Borrichius on burning glasses three or four 



feet in diameter. A. P. 1699- II. 90. 

 Tschirnhaus's large lens, of 32 feet focus. A. 



P. 1700. H. 131. 

 Parent on a tool for hyperbolic glasses. A. P. 



1702. H.92. 

 Cassini on centering glasses. A. P. 1710. 



223. 

 Homberg on the ancient burning glasses. A. 



P. 1711. H. 16. 

 Bianchini and Reaumur's stipport for large 



lenses. A. P. 1713.299^ 

 Hertel on grinding lenses. M. Berl. III. 



146, 

 Noilet's machine for grinding lenses. Mach. 



A. VI. 127. 

 Deparcieux's machine for grinding glasses. 



A. P. 1736. H. 120. Mach. A. Vil. 50. 

 Jenkins's machine for grinding spherical 



lenses. Ph.tr. 1741. XLI. 555. 



A cup and ball both revolving. 



Short's method of working object glasses truly 



spherical. Ph. tr. 176y. 507. 

 Delivered sealed 1753. 

 Zeiher on burning lenses. N. C. Petr. VII. 



237. 

 Euler on polishing lenses. N. C. Petr. VIII. 



254. 



For preserving the form. 



Euler on optical glasses. A. Berl. 1761. 107, 



147.1762. 117, 195. 

 Antheaulme on polishing object glasses. S. E. 



VI. 465. 

 Libaudeon making flint glass. S. E. 1773. 

 Cadet and Brisson onTrudaine's lens. A. P. 



1774. 62. H. 1. 

 Made of plate glass bent, with 1 40 pints of spirit of wine. 



On a spherometer for measuring lenses. Roz. 

 VII. 484. Fig. VIII. 398. 



Bunows's machine for grinding glass. Bai- 

 ley's mach. I. 142. 



E. M. A. IV. Art. Lunettier. 



Water lens. E. M. A. VI. 733. 



Canterzani on grinding lenses. C. Bon. VI. 

 O. 382. 



Achard on optical glass. A. Berl. 1788. 14. 

 1790. 40. 



Enc. Br. Art. Burroughs's machine. Glass po- 

 lishing, Lens. 



Diek Anvveisung vergrosserungsgl'aser zu 

 schleifen. Hamb. 1793. 



Macquer on flint glass. Repert. VII. 211. 



Globules for microscopes. Nich. I. 131. 



On optical glass. Nich. I. 180. 



On achromatic lenses. Nich. II. 233. 



Benzenbergon the improvement of flint glass. 

 Gilb. XI. 255. 



Dr. Benzenberg warmly recommends, that the glass be 

 suflFered to cool in the pots without stirring, and that the 

 mass be then divided in a horizontal direction, so that the 

 variation of density may be regular, and then, by a proper 

 form of the glasses, the errors of refraction may be correct- 

 ed. The idea is not new, but it does not appear to have 

 been carried into practice. Dr. Benzenberg considers 

 achromatic telescopes as promising much more than reflect- 

 ors, and thinks that they intercept much less light. 



The dishes in which lenses are sometimes ground are of 

 bell metal ; the emery is prepared by elutriation. The large 

 clumps now used for lamps are first formed in hemispheri- 

 cal ladles This mode was proposed by Gessner in 1726. 



Optical Scenery. 



Hook on forming pictures on a wall. Ph. tr. 



1668. III. 741. 

 Noilet's camera obscura. Mach. A. VI. 125. 

 Euler's improved magic lantern and solar 



microscope. N. C. Petr. III. 363, 

 fStorer's patent delineator, Repert. IV. 239. 

 A camera obscura. 



