' GALILEO'S ' AND CAMPANI'S MICROSCOPES 



127 



after and shown on p. 139. A -lens is mounted in a central aperture 

 in a polished concave metal reflector. Descartes apparently devised 

 another and much more pretentious instrument, but it appears im- 

 practicable and could never 

 have existed save as a sugges- 

 tion. But he appears to have 

 been the first to publish 'figures 

 >and descriptions for grinding 

 ;tnd polishing lenses. 



In the Museo di Fisica there 



FIG. 93. Campani's microscope (1660)? 



are two small microscopes which 

 it is affirmed have been handed 

 down from generation to gene- 

 ration since the dissolution of 

 the Accademia del Cimento in 

 1667, with the tradition of 

 having been constructed by 

 Galileo. They are shown in 

 fig. 92, but from the superiority of construction of these instru- 

 ments it is very improbable that they belong to the days of Galileo, 

 who died in 1642; and there is a specially interesting compound 



FIG. 92. Galileo's microscopes. 

 ? Campani or later. 



