608 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



believed that both Ericsson's and Wilcox's engines were fairly 

 entitled to be thus considered. Between five and six hundred of 

 the Ericsson engines, and some twelve or more of the Wilcox 

 engines are now in daily and successful use. 



Mr. Roosevelt inquired if the caloric yacht was not lying up — 

 was she a success. He had seen a boat driven by a six horse 

 power caloric engine which could be driven as well by two men 

 with oars. 



Mr. Stetson considered the engine successful for stationary 

 purposes. It would do, and was doing, in hundreds of instances, 

 the w^ork for which it M^as purchased, without involving any ex- 

 pense for attendance, or increasing the rate of insurance. It had 

 failed only where too much had been expected of it. It's too 

 enthusiastic friends — possibly the manufacturers — had rated its 

 power far too high, but there was danger that that fact would 

 induce an overlooking of what it really did successfully perform. 

 The question of the durability of the heaters had been raised by 

 the Chairman, and it was a very important one. The Ericsson 

 engine was obviously less durable than the Wilcox, but he felt no 

 hesitation in saying that even the Ericsson heaters were reason- 

 ably durable. Dodge & Grattan were printing at 56 Gold street 

 with an Ericsson engine which had worked from the spring of 

 1859 to the spring of 1860, and then was replaced by a larger 

 one which had worked without interruption down to the present 

 time. Mr. Stetson could not say positively that the heaters of 

 the first engine were seriously defective when the change was 

 made, but if the heaters of these engines did require a renewal 

 as often as every twelve months, the expense, as guaranteed by 

 the manufacturers, was only $15 — a mere trifle compared with 

 the salary of a competent engineer. 



The Chairman said that there was no light thrown on the side 

 of economy of fuel this evening. 



Mr. Stetson said that in steam engineering an engine of 200 or 

 300 horse power worked much more economically than one of 

 two or three. The air engines' were not more economical of fuel 

 than large steam engines, but were much more so than the small 

 steam engines for which they were substitutes. The present 

 engine at Dodge & Grattans — a 24-inch cylinder — required but 

 one hundred pounds of anthracite per day. He had not tested 

 its power, and declined to attach any importance to the " five 

 horse power " which had injudiciously been claimed for air 



