180 



Size and Weight.- -The size of instrument is 

 worthy of consideration. If an instrument is to 

 remain stationary in a practitioner's office or labo- 

 ratory, it may be large without being cumbersome. 

 If, however, it is intended to be carried about it 

 should be of the smaller and more contracted 

 pattern. 



Working Space Below Stage. Another im- 

 portant consideration is the space between the 

 stage and base, or table. While it is advisable to 

 have the stage low on account of the convenience 

 in manipulating a slide, there should "still be suf- 

 ficient space for the convenient attachment of sub- 

 stage accessories. In this respect the American 

 instruments, whether of the American or Conti- 

 nental type, are superior as they are built for the 

 better accommodation of accessories. 



Stage. A variety of stages is offered on in- 

 struments of similar construction. The plain, flat 

 stage while preferred by some, offers no advan- 

 tages over the ordinary round one, unless specially 

 made for examining specimens on larger slides than 

 the standard 3 by 1 inch. Those stages, covered 

 on top with vulcanite, offer many advantages. 

 The spring clips are usually of similar construction, 

 although varying in detail and curves. Properly 

 constructed clips should have such thickness of 



