PLATE XXXII 



Fig. I. — Zinc wall attached to outside of iron framework, \^itli all but the last 

 section shown in place : A , Openings in zinc wall to admit thermoelements as described 

 on page 332; B, hooks projecting outward from edge of channel irons, to support 

 water pipe for cooling zinc, as explained on page 335 ; C, sheet-metal tubes projecting 

 from holes in copper wall for passage of pipes for air entering and leaving the chamber, 

 as explained on page 304; D, tubes projecting from holes in copper wall for passage 

 of pipes for water entering and leaving the heat absorber, as explained on page 316; 

 E, passages for pipe carrying oxygen into the chamber (see p. 309), for wires for elec- 

 tric fan, electric light, resistance thermometers, etc.; F, supporting structtue for 

 chamber; G, supporting structure for cork board and outer covering. 



Fig. 2. — Devices for circulating and ptuifying air: A, Rotary compressor for main- 

 taining air circulation; B, motor for driving compressor; C, special bottles containing 

 sulphuric acid, for removing water vapor from circulating air; D, bottles containing 

 soda lime for absorbing carbon dioxid from circulating air; E, bottle containing sul- 

 phiuic acid for absorbing water vapor given up by the soda lime. 



