PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 365 



I contemplate certain small improvements which will lessen the con- 

 sumption of fuel in the streets. I design to heat the water at the stations 

 up to the temperature of the steam, and fill the boiler at the stations, and 

 not feed it on the way. This will save a quarter of the fire on the road, 

 and a quarter of the boiler surface, and the use of pumps, and will make 

 the engines, on the whole, lighter. A Giffard injector will be carried, but 

 never used except in an emergency. By using all such means that are 

 conveniently practicable we may reduce the noxious gases to much less 

 than they are with horse power — less than half on stone pavements, and 

 less than a sixth when horses are superseded, and we have iron floors. 



The dummies condense their steam. I have in this Club suggested that 

 in the winter we maj^, in a future and more civilized age, remove the snow 

 from the streets as soon as it has fallen, and preserve it to condense steam 

 in summer. Mr. Wm. A. Lighthall, who is known as the designer of the 

 engines of several first class steam vessels, has an air-surface condenser 

 which he believes will be efBcient on steam carriages. And w^e have 

 engineers, both here and in England and France, who believe that com- 

 pressed air may be used instead of steam, when machine vehicles have 

 come so much into use that compressing stations can be supported. But, 

 in the beginning, we must be content to keep the steam invisible, and 

 shoot it upward so that it maj^ be blown away from the city. This is done 

 in locomotives that keep their steam dry. Steam-jacketed cylinders help 

 to do it; superheating steam helps to do it; and the heat wasted in 

 upright tubular boilers helps to do it; that is, the exhausted steam, mixing 

 with hot gases in the chimney, becomes so hot as to dissolve in the air with- 

 out becoming cloudy. If you watch the cloudy steam from an engine that 

 does not exhaust into a chimney, you will see that it soon dissolves into the 

 air, and ceases to be visible; but locomotives that keep their steam dry, send 

 it out so hot that it dissolves in the air before it has time to become vesicu- 

 lar, or cloudy. 



Fourth, as to danger. Were I to build a steam carriage that would be 

 frightened by a wheelbarrow, or a push-cart, or an elephant, or locomotive, 

 or by any strange object, the ultra conservatives would regard it as a 

 serious objection to my carriage, and would not allow it to run, at the risk 

 of killing people. But when an inexpert driver fails to control a timid or 

 even a frisky horse, that is nothing new, and therefore they don't object to 

 it. I claim that the steam carriage is, in this respect, safer than the 

 horse; it cannot be frightened, and has no will of its own. If your horse 

 frightened my carriage I would agree that it should be forever prohibited; 

 why, then, should you not allow that if your horse has beeu trained in 

 cruelty, and is afraid of every strange object, he should not be suffered to 

 go in crowded streets where he may at any moment kill infirm people? I 

 should be glad to ask Mr. Rarey if he could not easily train horses so that 

 they would consider locomotives rather agreeable companions. I think he 

 could. I know it has been done; and I think he could teach others to do 

 it; and the small minority of horses that would be frightened by steam 

 carriages could easily be got to like them. It is an exaggerated appre- 

 hension of the disputatious opponents of every new idea, that they do not 

 themselves originate, and not the timidity of well used and well trained horses, 



