48 



be arranged, should be devoted to this purpose only. 

 One with a round or square top of three feet provides 

 ample room. Although not necessary, a table with a 

 revolving top, provided with clamp, is very conven- 

 ient, as with this two or more persons may make 

 observations without changing their seats. 



A very neat arrangement for a table-top is that sug- 

 gested and used by Dr. J. E. Reeves. He places upon 

 an ordinary table three or four thicknesses of white 

 paper and upon these a plate of polished glass as 

 large as the top ; this can be procured of almost any 

 glazier at a low price. It is pleasant to work upon 

 and will not soil. 



As in almost all cities there is more or less contin- 

 ual vibration from wagons upon the paved streets, the 

 writer suggests an effectual remedy. Take a thin 

 board, say half an inch thick, of a sufficient size to 

 receive the microscope ; fasten on the upper side at 

 two opposite ends, cleats of 1 inch square and coun- 

 ter-sink into these through the board four spiral 

 springs of such tension that when they bear the 

 weight of the instrument, the bottom of the board 

 will be about \ inch from the table. 



Have the working table provided with drawers and 

 arrange receptacles for the accessories, secure from 

 dust, but at a convenient point to reach. When the 

 instrument is not in use put it into its case or cover 

 it in a manner so that it shall be free from dust. For 

 this purpose a large bell glass is best. 



