PLATE XXXI 



Fig. I. — Structiiral iron framework for respiration chamber: A, Sills and ceiling 

 plates of angle iron; B, studding and joists of light weight channel iron, with narrow 

 edge; C, asbestos building lumber to support copper floor; D, supports for exterior 

 cover of cork board and museum board. 



Fig. 2. — Copper- walled chamber attached to inside of iron framework: A, Bolts for 

 attaching wall to structure; B, wooden insulation between iron and copper; C, 

 thimbles soldered to outside of copper wall to receive inner end of thermoelement 

 described on page 331. 



