MECHANICS AND USEFUL ARTS. 57 



of furnace, particularly applicable where intense heat is required. The fur- 

 nace, as at present constructed, is applied to the melting of metals. A 

 number of zigzag passages are formed of fire-brick. There are two fires, 

 and the draught to and from each passes alternately along these passages. 

 So nearly is the heat absorbed that what ultimately escapes up the chimney 

 is only at about 200 to 300 degrees Fahrenheit. It had been used for about 

 three months in a furnace for iron and steel, and the result showed a saving 

 of seventy-nine per cent, as compared with the old furnace, turning out the 

 same quantity of metal. Mr. Atkinson, of Sheffield, observed that they 

 had one of those furnaces, and found the consumption to be so small that 

 he had the particulars noted during six days, of twenty-four hours per day ; 

 the consumption was one ton, ten hundred weight, while the consumption 

 for the same period by the old furnace was seven tons ; each furnace doing 

 the same description of work. The furnace had been applied to the melting 

 of caststeel with favorable results. The average of melting steel was gen- 

 erally five tons of coal to one ton of steel, but with this furnace they melted 

 a ton of steel with a ton of coal. Besides this, there was no smoke what- 

 ever; and if this furnace became general in Sheffield, of which he had no 

 doubt, they would be in a position to vie with any atmosphere in the world. 

 In answer to a question as to whether the changing of the currents in the 

 regenerator thus letting in cold air upon them after they had become 

 highly heated did not damage the brick-work ? Mr. Siemans explained 

 that in case the cold air came first against the part less heated, then against 

 the next, taking up one hundred or two hundred degrees at each stage, and 

 on this account no cracking from contraction took place. It was also in- 

 quired how the iron could be improved by this plan ? Mr. Siemans replied 

 that the puddling had not been long tried, but he thought it might arise in 

 this way : In the ordinary furnace there was a violent draught, but in this 

 the draught was small, and the flame did not cut the iron ; it gave an intense 

 heat, with a comparative quiet atmosphere, thus less oxide of iron was pro- 

 duced. The iron must also be more pure, because fewer particles were car- 

 ried over to it from the fire. 



Lecd's Hydraulic Heater. The main feature of this invention is the cast- 

 ing, in one piece, of several parallel pipes, in a straight row, with square 

 ilanges at each end. The four sides of the common flanges are planed so 

 that, to build up a tubular boiler, it is simply necessary to put the several 

 sets of parallel pipes one above the other, to insert a piece of oil paper be- 

 tween the flanges to perfect the joint, and to press the whole tight by a few 

 bolts. The water reservoir, containing the pipes, is closed by bolting against 

 the flanges of the pipes a top, a bottom, and two sides. The pipes are hex- 

 agonal, this being the best geometrical form to bring the pipes of one row 

 under the intervals of the one immediately above, so as to occupy the smallest 

 possible space. The bottom and the sides of the water reservoir are corru- 

 gated hexagonally, so as to correspond with the intervals between the pipes, 

 and produce a larger heating surface. The boiler is inclosed in brick work 

 over a fire grate. The flames pass under the bottom, and if this is not suf- 

 ficient are made to return along the sides, and so heat the water contained 



