Popular Science Monthly 



895 



weaken the metal walls of the still, 

 which in time will cause leakage of am- 

 monia-gas. 



It may be said that any compression 

 machine can be used with any volatile 

 refrigerant that will boil at 30° F., or 

 under, when exposed to the atmosphere, 

 but in practice certain minor differences 

 are o b - 

 served in 

 the con- 

 struction 

 of the ma- 

 chines on 

 account of 

 the differ- 

 ences in 

 pressure of 

 the various 

 refriger- 

 ants used. 

 Inasmuch 

 as all the 

 machines 

 above re- 

 ferred to 

 are prac- 

 tically au- 

 tomatic, 

 and can 

 be run, 



and are being run, without a skilled 

 attendant, it is hard to understand 

 why such machines are not more 

 generally used. 



The high cost of the first installation 

 is probably the largest obstacle to their 

 very general use. Take a machine whose 

 first cost is $900 and whose life is, say, 

 ten years, you have a fixed charge of 

 about $12.00 per month. Add to this 

 the cost of electric current, and the cost 

 of whatever repairs and adjustments 

 may have to be made by skilled experts 

 during the life of the machine, and you 

 have a bill considerably in excess of the 

 cost of 100 pounds of ice per day. 



One of the most objectionable fea- 

 tures urged against compression ma- 

 chines is the noise made by the motor 

 and compressor. P2ven when the ma- 

 chine is located in the basement it can Ije 

 heard over most of the house, and at 

 times such noise is deemed very objec- 

 tionable. Another cause of trouble is 

 in securing a constant and even flow of 

 cooling water to the condenser, where 



An absorption machine, though expensive to install, ought 

 soon to repay the initial cost 



constant running cooling water is used. 

 In many places the water supply con- 

 tains sediment or dissolved minerals 

 which will tend to collect under the con- 

 trolling valve and diminish the flow of 

 water. 



Most people imagine that the tem- 

 perature in an ordinary ice-cooled re- 

 frigerator 

 is lower 

 than it 

 really is 

 and when 

 they in- 

 stall a re- 

 f rigerat- 

 i ng ma- 

 chine they 

 try to keep 

 the tem- 

 perature 

 down be- 

 low 40° F. 

 The insu- 

 lation in 

 the ordi- 

 nary re- 

 frigerator 

 is not suf- 

 ficient to 

 maintain 

 such temperature and hence the use of 

 electricity to run the machine will be 

 excessive. 



When the public is fully aware of the 

 great advantages, sanitary and other- 

 wise, of this character of cooling, over 

 the ice-refrigerator plan, the difference 

 in cost, it is believed, will be cheerfully 

 accepted. 



The actual cost to build a machine of 

 this character that sells for $900 is 

 probably not one fourth of that amount. 

 It is fair to presume that the first cost 

 price of all these machines will soon be 

 materially reduced. 



Unfortunately, several machines have 

 been put on the market which were 

 faulty in design and involved engineer- 

 ing defects which made their failure a 

 certainty, and these failures hav^e cast 

 a shadow on the really meritorious ma- 

 chines. 



All the difficulties and obstacles tend- 

 ing to prevent a commercial success of 

 these machines are apparently capable 

 of being overcome by engineering skill. 



