Proceedings of the Polytechnic Association. 939 



found. This understood, with all the able committees and presidents 

 to study the problem of overcoming the difficulties, it can hardly be 

 supposed long to escape a solution. It must be acl%nowledged that 

 there are, it would now seem, a great majority of articles which can- 

 not by any means yet imagined be tested. It would be difficult, for 

 example, to test the efficiency of a novel style of lightning-rod, the 

 permanency of an ink, or the durability of a piece of timber saturated 

 with some novel chemical ; and such articles must continue to be 

 judged by their composition and appearance alone. Plow large a 

 number of articles may be made to stand practical tests during, or in 

 connection with, our ordinary annual fairs, can only be ascertained 

 by experiment. 



A toleral)ly full summary of the results of the test of stationary 

 steam engines, at the twenty-ninth Annual Fair of the American 

 Institute, may serve to illustrate both the good effects of such tests 

 and the difficulties attending their introduction. 



The fairs of the succeeding autumn are usually advertised in May 

 or June, with a programme of the premiums to be awarded. Among 

 those on which some stress was laid last year, was the offer of a gold 

 medal to be best, and a bronze medal to the second best steam engine ; 

 the engines to be tested practically in the presence of a committee of 

 five disinterested gentlemen, to be selected from as many different 

 States, in order to avoid, as far as possible, any local preferences or 

 prejudices. This w^as, as will appear, too magnificent a programme 

 to be carried out in the present state of exhibitioneering. A definite 

 size and proportion was prescribed, each cylinder to be twelve inches 

 in diameter, with three feet stroke of piston, in order to avoid all pos- 

 sibility of dispute in regard to the advantage or disadvantage due to 

 a difference in these respects; but this was afterward so far waived, 

 that the only two engines finalh' tested differed considerably in these 

 important points. The points on which the awards were to be deter- 

 mined were advertised to be as follows : 1st. Economy, or the 

 development of much power with a small consumption of steam. 

 2d. Eegulation, or the uniformity of the motion under diiferent con- 

 ditions ; and 3d. Cheapness, or the moderate expense of the machines 

 for first cost and repairs. These points were kept prominently in 

 view during all the postponements and alterations in the progranmie; 

 and the results given below, though not nearly as full as could be 

 desired, are of considerable interest in showing, or tending to show, 

 the economy and regulation of the non-condensing steam engine of 

 the present day. 



