Fig. 45. NACHET'S TRIPLE MICROSCOPE. 



THE MICROSCOPE. 



CHAPTEE YI. 



83. His object-glasses. MESSRS. SMITH AND BBCK'S MICROSCOPE : 84. Their 

 largest and most efficient instrument. 85. Their smaller microscope. 

 86. Their object-glasses. 87. Varley's microscope. M. NACHET'S 

 MICROSCOPE : 88. Their adaptation to medical and chemical purposes, 

 89. Multiple microscopes. 90. Double microscope. 91. Binocular 

 microscope. 92. Triple and quadruple microscopes. 



83. WITH his largest and best instruments, Mr. Ross supplies 

 four eye-glasses and eight object-glasses, by which thirty- two 

 varieties of power and illumination may be obtained. The object- 

 glasses vary from two inches to a 12th of an inch in focal 

 length, and from 12 to 170 in angular aperture. The following 

 LARDNER'S MUSEUM OF SCIENCE. o 81 



No. 116. 



