1896.] 



MICROSCOPICAL JOURNAL. 



13*7 



the microscope must be upturned or the investigator is 

 obliged to place his liead on the level with the table, 

 thereby upsetting rc-agent bottles or provoking other 

 mirth and mischief before he is enabled to focus his tube 

 correctly and with safety on some valuable slide. This 

 has been the writer's experience, and now that he has 

 finally and • so simply solved this perplexing (piostion, 

 submits his discovery to the society, with considerable 

 feeling of pride and gratification. 



On the diapliragm in the large part of the objective, 

 or the end that is screwed to the nose-piece, the desig- 



nation of the lens may be engraved, so that when the 

 nose-piece is revolved the designation of the various lens- 

 es will be at once visible. The in vestigator with one eye 

 at the ocular, need not change his position in bringing 

 all the lenses under tlie ])0(ly tube, but can with the other 

 eye see the lens as it swings into place, and can focus 

 with coarse and fine adjustment accordingly. The writer 

 has been well pleased with the focal lengths of the Zeiss 

 objectives, necessitating but one focusing for all the diff- 

 erent lenses, especially of the dry system. Working with 



