which may be commended to those who wish to 

 study more deeply the principles of the microscope 

 and learn its history and development. 



The writer trusts that omissions will be pardoned, 

 as the only time which it has been possible to 

 devote to this work has been the spare moments of 

 a busy life and hopes sufficient information may 

 be obtained to give full compensation for such 

 defects. 



THE AUTHOR. 

 March 1, 1897. 



