200 Management of Conical Boilers. 



obtained cheap, I consider Welsh coal decidedly superior to any 

 other ; the next best being coke breeze freed from dust by a 

 sieve of the quality mentioned above. It is, perhaps, hardly 

 necessary to observe, that the consumption stated above is that 

 of a 10-inch boiler. As the boilers are proportioned to their 

 work, a 13-inch will require nearly double ; a 15-inch about 

 three times the above given quantities of fuel. 



The foregoing details supply every information which can be 

 desired by those who employ this boiler; they show what may 

 be expected of it, and how its utmost efficiency may be attained. 

 I have been particular in detailing them, because they are simple 

 and easily followed, and will, I know, insure success. 



In conclusion, I would observe that a strict adherence to the 

 instructions contained in my former paper, as to fixing, &c., is 

 essential to the efficiency of this apparatus. If those instructions 

 are observed, its efficacy is certain; but, in proportion as they 

 are neglected, it will partially or entirely fail. I must at the same 

 time remark that there is no complexity or difficulty about its 

 operation : if it be once properly put up, its management is 

 exceedingly easy and simple. 



With respect to the boilers themselves, I recommend every 

 one who wishes to employ them to apply to Mr. Shewen ; be- 

 cause I know that those manufactured by him are precisely in 

 accordance with my instructions, and a very slight deviation 

 from their form may materially impair their efficiency. I have 

 no pecuniary interest in the invention, nor was it ever my in- 

 tention to appropriate it with that view. But, if I could have 

 foreseen, when I first published in 1837, the experience of Dr. 

 Arnott's stove, I should probably have taken out a patent to 

 prevent imperfect imitations ; as it is, I can only hope to attain 

 that end by recommending a person who works under my eye, 

 and adheres to my instructions ; and I believe Mr. Shewen will 

 be found able and willing to furnish the article upon the most 

 reasonable terms on which it can be effectually manufactured. 

 He will also undertake to fix the apparatus where it is desired ; 

 but, by a close adherence to my instructions, any intelligent 

 gardener may direct the fixing of it himself. With respect to 

 other persons who may think it worth while to manufacture these 

 boilers, they will do well to adhere as closely as possible to my 

 instructions. 



The conical boiler, in its present form, is the result of con- 

 siderable study, of some experience, and of deliberate design ; 

 and I am doubtful whether it can be materially improved. T shall, 

 nevertheless, be most happy to receive any suggestions on the 

 subject; but I must request that those who make them will first 

 take the trouble to understand what they write about; and, with 

 this view, I recommend to their attentive perusal Mr. Charles 



