Journal of Applied Microscopy. 



125 



to him to indicate what is necessary to 

 carry on the work. To facilitate this 

 labor, and to make easily accessible a 

 knowledge of the cost, place of purchase 

 or the time required to obtain any piece 

 of apparatus or any material needed 

 in the laboratory, the catalog blank 

 (Fig. 1) has been evolved during the 

 last 10 years. The card has been filled 

 out in script from an actual case. In ad- 

 dition to the information given in this 

 card, there is usually present a mark 

 showing where the apparatus is to be 

 found, thus adopting the principle of 

 shelf marking used in libraries. 



To facilitate the understanding of the 

 metric system which is required in all 

 our work each student is supplied with 

 a card of the standard size used in 

 library catalogs, shown in Fig. 2. 



ocular, but the majority find it hard to 

 do this. Various eye shades have been 

 devised to obviate the trouble. 



Fig. 3. Laboratory Table, adjustable stool, 



water and waste jars, and screen. 



The most convenient size for a labora- 

 tory table is about 125 cm. long, 72 cm. 

 wide, and 72 cm. high, (48 in. long, 2S m. 

 wide and 28 or 29 in. high); and for a 

 seat, an adjustable piano stool, costing 

 from $1.50 to $2.00. 



For the most critical microscopic work 

 one most conveniently faces the light; 

 this is hard on the eyes and hence some 

 form of a screen is exceedingly useful. 

 Those figured in Fig. 3, 4 were made by 

 inserting a wire in a tin patty dish and 

 filling the dish with lead. The wire is 

 bent at right angles and a sheet of heavy 

 paper high enough to screen the eyes and 

 low enough to shade the stage, but not 

 to interfere with the mirror is hung on 

 the bent wire. 



Many workers find no difficulty in 

 keeping both eyes open, simply neglect- 

 ing the images of the eye outside the 



Fig. 4. Screen for shading the microscope 

 and the face of the observer. 



One which has the advantage that it 

 may be used for either eye and thus en- 

 courages the use of the eyes alternately 

 is shown in Fig. 5. 



7 X ^4 '^'w- 



/o 



Fig. 5. Double Eye-Shade. This is readily 

 made by taking some thick bristol board 

 7 X 14 centimeters and making an oblong 



opening with rounded ends (o o) and of 



such a diameter that it goes readily over 

 the tube of the microscope. This Is then 

 covered on both sides with velveteen and 

 a central slit (s) made in the cloth. This 

 admits the tube of the microscope and 

 holds the screen in position. It may read- 

 ily be pulled from side to side and thus 

 serves for either eye, or for the use of the 

 eyes alternately. 



Twenty years experience has shown 

 that in a laboratory there must either 

 be a microscope for each student, which 

 is the best plan — or some arrangement 

 by which two or more can use one mi- 

 croscope and be held responsible for it. 

 The form of cabinet finally adopted is 

 shown in Fig. 6. 



The outside doors put the entire equip- 

 ment under the control of the teacher. 

 The small lockers make it possible to 

 gfve each microscope to a definite num- 

 ber of students, who can be held 

 accountable for it. 



In order that specimens may have a 

 neat appearance and be uniform, it is a 



