240 PROCEEDINGS OF THE AMERICAN ACADEMY 



ing upon his engine, chiefly with a view to secure as great economy 

 in fuel as possible. He has sold several engines, however, which seem 

 to have given satisfaction, and has now several others nearly com- 

 pleted. He has increased the power of his engine considerably by 

 adding a small tubular boiler, in which steam is generated by the heat 

 of the exhaust air. This boiler communicates with his reservoir of 

 condensed air, and increases and equalizes the pressure. The Commit- 

 tee have found his estimates of the power of his engines correct. 

 Those from two to three horse-power consume about 2J- pounds of 

 coal to the horse-power per hour. None of his engines have been 

 in operation long enough, however, to put their practical success 

 beyond question, although one of them has now been in constant 

 use for four months, giving satisfaction to its owner. The Committee 

 believe that Mr. Shaw has, or will have, after a few changes, a suc- 

 cessful engine. 



"Mr. Roper's experiments have been directed rather to improve- 

 ments in other respects than to securing economy in fuel. Plis engine 

 has been greatly improved since the last report of the Rumfoi'd Com- 

 mittee. Mr. Roper has finally settled on the form which he will re- 

 tain, and has begun to manufacture engines from it on a large scale. 

 The ease with which this engine can be repaired, and the facilities 

 which its construction afford for its manufacture in great numbers, will 

 probably lead to its very general use. It consumes not more than 

 five pounds of coal to the horse-power per hour. The Committee be- 

 lieve this to be the most successful hot-air engine now at work in Bos- 

 ton. The largest size made, up to this time, is two-horse-power." 



Dr. B. A. Gould presented a report from the committee ap- 

 pointed to consider the intent of the statutes concerning the 

 election of Fellows. The report was accepted, and a recom- 

 mendation to modify the statute, Chapter IX., Section 2, by 

 substituting the words " at least ten weeks," for the words 

 " the interval between two stated meetings," was referred to 

 the Committee on amending the Statutes. 



Dr. B. A. Gould was excused from serving on the commit- 

 tee, and the President was appointed in his place. 



The following gentlemen were elected members of the Acad- 

 emy, viz. : — 



