( 22(5 ) 



" is removed farther from the magnifying lens, or admitted nearer to it, by 

 " a little fcrew, I, that, paflTmg through the flage horizontally, and bearing 

 " againft the back of the inftrument, thrufts it farther off when there is oc- 

 " cafion. The end of the long fcrew, g, comes out through the ftage, at m, 

 " where it turns round, but afts not there as a fcrew, having no threads that 

 " reach fo high. Thefe Microfcopes are plain and fimple in their contrivance : , 

 " all the parts are filver, fafhioned by M. Leeuwenhoek's own hand, and the 

 " glafTes, which are excellent, were all ground and fet by himfelf. 



" The magnifying powers of thefe glafles come fhort of fome now made, 

 " but are fully fufficient for mod purpofes. Of the twenty-fix Microfcopes 

 " I examined, one magnifies the diameter of an objeQ; l6o, one 133, one 

 " 114, three 100, three 89, eight 60, two 72, three 66, two 57, one 53> 

 " and one 40 times," 





♦ 



