130 Nolke of the Conical Boiler 



one of these boilers to the council of the Horticultural Society, 

 and its merits were satisfactorily proved in the Society's Garden, 

 and made known to the fellows, and ultimately to the public at 

 large, through the Gardener^s Gazette, Gay^dcncr's Magazine, 

 Paxton's Magazine of Botany, Q.nd other periodicals, all of which 

 overlooked the original inventor so far as to allow him no share 

 of the merit of this very useful invention. 



The boiler is yet susceptible of improvement. In its present 

 form it is made up of two concentric cones, joined at top and 

 bottom by flanges sufficiently wide to leave a space of one or two 

 inches between them for the water. The fire is applied in the 

 inner cone. There is a defect in the outset, which is soon de- 

 tected in practice. As soon as the fire begins to burn clear in 

 the inner cone, the heat is. generated faster than the small body 

 of water can absorb it, and steam is soon produced. There is a 

 small pipe fixed in the top of the boiler with a steam valve to 

 guard against accidents. By close attention to the fuel and 

 damper, this steam might be avoided, and only as much heat 

 produced as could be absorbed by the water ; but this requires 

 too great a nicety for so simple an apparatus. Instead of having 

 the inner part of the boiler a cone, let us have it more of a cy- 

 lindrical form : this would reduce the size of the fire and the 

 surface to be heated, and it would increase the space for the 

 water in the same ratio. Probably some modification of this kind 

 would simplify the working of the boiler by producing no more heat 

 than is absorbed by the water. At any rate, we must get rid of the 

 steam, at least till the water in all the pipes is heated to 200°. 



It were desirable that those who use this boiler, and think 

 they could suggest any improvements, would convey their ideas 

 to Mr. Shewin, as above, or to some other enterprising iron- 

 monger or engineer, in order that we may have the benefit of 

 this most excellent invention to the fullest extent. The very 

 great saving in fuel, the almost entire absence of smoke, and the 

 ease with which it can be attended, will cause it to supersede all 

 other forms of boilers now in use ; and there is no reason why 

 it should not be made sufficiently large to suit houses of any 

 size. An article, like this boiler, which must soon come into 

 universal use, will, no doubt, be taken up by several tradesmen 

 for the sake of profit, and several modifications of it in consequence 



was an invention to which Mr, Rogers was led by a series of experiments 

 founded on certain principles, and having a certain object in view. Mr. Rogers 

 tried a vertical cylinder first, which did not answer perfectly, wasting much 

 heat. He then employed a cone, which succeeded better. But for Mr. 

 Shewin's perseverance in accomplishing the object in cast iron, it is doubtful 

 whether it would ever have become of general service ; as Mr. Rogers's original 

 boiler was made of copper, which was much more expensive, and, as it proved, 

 much less durable, than iron. — D. B." 



