700 SCIENCE. [N.S. Von. XIII. No. 331. 
They are supported on racks of four shelves two of them each controlling the six places 
each, six cells per shelf. Each shelf is on their respective sides of the room, and 
thoroughly paraffined and a half inch layer the third controlling the four places in the 
of ground quartz placed around the jars. center. The face of one of these boards is 
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Fia. 3. Electrolytic Laboratory. 
Fig. 4 shows one of these compartments shown in Fig. 5, the letters on the face re- 
with the lead wires and cut-outs for each ferring to the working tables contrulled. 
cell. ‘The switchboard on the east side of the 
‘The switchhoards are three in number, room consists of a slab of enamelled slate 
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Fie. 4. Battery Room, 
