1869.] 



of Ice and Cold. 



205 



is based aj^pears to be erroneous, and it is not likely to be effective 

 for refrigeration, besides which their apparatus is far too comj^li- 

 cated in its arrangements. Several other patents have been taken 

 out for ice-making machines, but those already mentioned are the 

 principal ones which have been tried. 



An improved form of the ammonia apparatus, which comprises 

 some novel features of very great importance in regard to the use 

 of that material for refrigeration, was patented by Mr. Eeece * in 

 1867. The arrangement of this apparatus is shown by Fig. 4. 



Fij?. 4. 



The boiler a is charged with water or a very weak solution of 

 ammonia, and the steam, discharged under a pressure of 100 lbs. 

 per square inch, passes by the pipe a a to the bottom of a Coffey's 

 analyzer, b, consisting of a tall columnar vessel with a series of 

 plates arranged one above the other inside. Into the top of this 

 vessel a concentrated solution of ammonia is pumped continuously, 

 and in descending from plate to plate it meets the ascending current 

 of high-pressure steam, the effect of their contact being to convert 

 the ammonia into gas, while the steam is condensed and flows back 



* Specification, No. 1621. 



