CARE OF THE EYES; WORK TABLE 



[CH. Ill 



remaining nearly in a condition of rest as for distant objects. The 

 fatigue incident upon using the microscope at first is due partly at 

 least to the constant effort on the part of the observer to remedy the 

 defects of focusing the microscope by accommodation of the eyes. 

 This should be avoided and the fine adjustment of the microscope 



used instead of the muscles 

 of accommodation. With 

 a microscope of the best 

 quality, and suitable light 

 - that is, light which is 

 steady and not so bright 

 as to dazzle the eyes nor 

 so dim as to strain them 

 in determining details 

 microscopic work should 

 improve rather than injure 

 the sight. 



If artifidal H ht mUSt 



F,c. S 8. M.CROSCOPICAL LABORATORY DESK 



be used, give it daylight 



WITH MICROSCOPE AND CHALET LAMP. 



(Desk designed by Dr. V. A. Moore about one qualities by placing a piece 

 twentieth natural size.) of ground daylight glass 



The size of the top and the height are the between the source of light 

 same as for the laboratory table (fig. 57, 162). 



m At the right there is a cabinet with com- and the microscope. This 



bination lock (10, d) for a microscope, and w ;ii p.j ve one a verv so f t 

 above a drawer with combination lock (a,d). 



At the right is a writing shelf (5) and four hght like that from a white 



drawers (b, c, d, e.} rlond (S 02") 



Near the bottom is a brace (br) which also 



serves as a foot rest. 162. Position and 



M Compound microscope with the Chalet chara cter of the work- 

 Microscope Lamp in front of it. 



table. -- The work-table 



should be very firm and large (61 X 122 cm. on top, and 73 cm. 

 high; 24 x 48 X 29 in., fig. 57), so that the necessary apparatus 

 and material for work may not be too crowded. The table should 

 also be of the right height to make work by it comfortable. An ad- 

 justable stool, something like a piano stool, is convenient; then one 

 may vary the height corresponding to the necessities of special 

 cases. It is a great advantage to sit facing the window if daylight 

 is used; then the hands do not constantly interfere with the il- 



