554 transactions of the american institute. 



American Institute, Polytechnic Association, 



November 8, 1866. 



Prof. S. D. Tillman in the Chair; T. D. Stetson, Eaq., Secretary. 



The Avery Reacting Steam Engine. 



A very interesting relict of the past, presented to the Institute 

 by Wm. Avery Sweet, Esq., President of the Onondaga steel 

 works, called the Avery steam engine, was exhibited. It consists 

 simply of two flat hollow arms, shaped like oar-blades, which are 

 fastened to a hollow shaft through which steam enters and is dis- 

 charijed near each end, but on opposite sides of the blades. The 

 blades move in an opposite direction to which the steam is dis- 

 charged. A circular box usually encloses the revolving arms 

 from which a pipe conducts the exhaust steam. 



The chairman remarked that the Avery engine was the most 

 improved form known of the oldest engine on record. The 

 ^olipile, said to have been invented by Hero, of Alexandria, 

 was in tact a boiler and engine, for the arms, instead of being 

 fastened to a hollow shaft, were connected with a hollow globe 

 less than half filled with water, and under which a fire was made. 

 The JEolipile should not be dignified with the name of steam 

 eno"ine, for it never could have worked eflectively; but while the 

 water in the globe was boiling, it served to show that motion 

 could be obtained by the escaping steam. The Avery engine 

 does not move by virtue of the escaping steam pushing on 

 the atmosphere, as max\y suppose, for the arms will revolve in a 

 vacuum. It moves by the reacting pressure of the steam which 

 is o-reatest on that side of the hollow arm opposite to the minute 

 hole throuo-h which the steam is discharged. It is quite evident 

 that but fifty per cent, of the full power the escaping steam can 

 be utilized. Even this per cent, can only effectively be applied 

 by arms revolving at very high velocity. In the engine now 

 exhil)ited, with steam at 100 pounds pressure, the whole power 

 applied would not exceed five pounds at the end of each arm, but 

 as the arms made more than one thousand revolutions per min- 

 ute, it will l)e found by calculation that, when geared down to run 

 slow, the driving wheel had great power. 



All attempts to make an economical reacting steam engine have 

 proved futile. Yet this engine in some kind of work has been 

 very serviceable; and where fuel was of no value, as for instance 

 in a backwood's saw mill, and high speed was required, without 



