i 66 Description of a Portable Chamber Blast-Furnaee. 



dex to the person who attends the fire, nothing more being; 

 necessary for this purpose ihan to graduate the arch de- 

 scribed by the end of the rod Q_Z. In the side of the 

 steam-box C there is an opening N to allow the steam to 

 pass from it by a pipe or tube to the steam-engine, or to any 

 secondary boiler, or for the purpose of conveying and ap- 

 plying it to any other vessel or use to which steam is appli- 

 cable. 



Before dismissing this article, we must beg our readers to 

 correct an error in printing the description of the boiler in 

 our last number, page 41. The second line from the bottom 

 should read " not joined to any of them, excepting th^' 

 middle one, at the points," &c. 



XXVII. Description of a Portable Chamber Blast Furnace* 

 By C. K. AiKiN, Esq, 



To Mr. Tilhch. 



DEAR SIR, 



OoME of my chemical friends having expressed their ap- 

 probation of a small portable blast-furnace which my bro- 

 ther and myself have been in the habit of using for a 

 variety of experiments on a small scale ; I am induced to 

 send you a description of it, in hopes that it may prove as 

 serviceable to others as it has been to us. It is particularly 

 adapted to those who, like myself, can only devote a small 

 Toom and a moderate share of time to these pursuits. 



Dr. I^ewis in his Commerce of the Arts (page 27) de- 

 scribes a very powerful blast-furnace formed out of a blackr 

 lead pol, which " has a number of holes bored at small di- 

 stances in spiral lines all over it, from the bottom up to 

 such a height as the fuel is designed to reach to." This is 

 let half way into another pot, which last receives the nozzle 

 of the bellows, so that all the air sent in is distributed 

 through the spiral licJes of the upper pot, and concentrates 

 the heat of the fuel upon the crucible, which is placed in the, 

 midst. 



The furnace v/hich I am going to describe resembles very 

 clbsely this of Dr. Lewis; with this difference, however, that 

 the air-holes are only bored through the bottom of the pot, 

 and this merely stands upon another piece, instead of being 

 let into it. It is on this account somewhat more commo- 

 dious, and I imagine not- less powerful. 



Fig. 1. (Plate V.) is a view, and fig.. 2. a section of the 



furnace. 



