646 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



sible to the engine and its receiver, whenever and wherever re- 

 quired ; fixing the compressing stations at distances apart of 

 twenty miles or more, and those for delivery to the engine at 

 such convenient distances as may become necessary, depending 

 on size of receiver, duty of the line, grade to be traversed, and 

 other conditions which experience will not be slow to indicate ; 

 communicating reservoir to be tapped at those points where de- 

 livery is required, and there a communication to be established 

 between reservoir and receiver, in such manner that the re-sup- 

 ply required to propel the engine with its load to the next point 

 of its journey, shall be furnished in a few seconds of time without 

 necessarily stopping for that purpose. That method, in our own 

 country, has been both devised and patented. 



But, as the proposition is, for the present, to apply the com- 

 pressed air power to city routes, and as these routes will be found 

 not to exceed the distance, which a carriage, provided with the 

 power, may run without replenishing, with the supply of com- 

 pressed air originally furnished to it at the starting point ; there is 

 no immediate occasion to more particularly describe the arrange- 

 ment by which the replenishing process is to be carried out. For, 

 if an air carriage may be propelled by the power packed up, at the 

 starting point, in its own receiver, a distance, according to the 

 suggestion of Mr. Parsey, of twenty or thirty miles ; or even ac- 

 cording to our own theory, which is fully borne out by Mr. Par- 

 sey's experiments, eight miles ; there would be no necessity for re- 

 plenishing the power, for Broadway in our own city for instance, 

 till the return to the starting point. Even if that distance 

 should not exceed four miles that assumed by Mr. Stetson, and 

 expressed with emphatic confidence, in reply to a question pro- 

 pounded by your chairman on the first occasion of introducing 

 the discussion, one replenishing station only, would be requisite, 

 and for that a space of ten feet square might be had at the bat- 

 tery, which could not be devoted to a better purpose. 



The English engineers evidently thought of nothing short of 

 long routes when bringing their experiments before the public. 

 For, the idea had scarcely begun to be entertained, at that time, 

 in England, of putting railways for city travel in their streets, 

 as we have done for years past. It is only within a recent period 

 that horse cars have been run in any of their larger towns, after 

 the fashion in vogue here. There being, then, no short or city 

 routes in use there, or in contemplation, at the time of those 



