U. S. NATIONAL MUSEUM 



BULLETIN 173 PLATE 3T 



Refrigerating Machines. 



1. Audlffren refrigerating machine, 1913 (U.S.N.M. no. 311060). Seep. 183. 

 2. Frost-Maker domestic refrigerating unit, c. 1914 (U.S.N.M. no. 311358). See p. 184. 



