MECHANICS AND USEFUL ARTS. 51 



Finally, that nothing may be omitted, we must mention certain trifling 

 accidents which are apt to occur with the Beaufume' apparatus. These are 

 miniature explosions which take place on igniting the gases in the boiler 

 furnace, when the precaution is not taken of shutting off the supply of air 

 until the moment when the light is applied, and when in consequence the 

 furnace and flues arc rilled with carbonic oxide, mixed with air. There is, 

 however, not the slightest danger attending these explosions, for the flames 

 do not reach far on account of the very slightly-elevated temperature of the 

 gases. 



A commission of the French government, appointed to examine and re- 

 port on the new apparatus during the past year, presented the following 

 summary : 



M. Beaufume" s heating apparatus works with perfect regularity ; is quite 

 free from smoke, and effects a great saving. The saving derived from it as 

 compared with the ordinary system of heating, reached as much as thirty- 

 eight per cent, in our experiments, and there is no doubt that the very great 

 saving of one third may be reckoned upon with certainty. 



There are no difficulties in working the apparatus ; it requires but a little 

 extra care and attention, but not so much as to constitute a matter of seri- 

 ous consideration. 



It has the advantage, above all, of being able to use economically fuel of a 

 kind which can only be burnt in ordinary furnaces with great difficulty, such 

 as small coal. 



It has the inconvenience of throwing a quantity of carbonic oxide into the 

 boiler house, and, although this is not of much importance on land, it might 

 be serious on board ship. This defect is less, the less frequently the fuel is 

 stirred up, and, with some coals, it scarcely exists, as they do not require 

 stirring up. We must also remark, that, although M. Beaufume's apparatus 

 has reached a practicable state, it is still too recent an invention to be inca- 

 pable of improvement, and M. Beaufume' hopes, and we believe it quite pos- 

 sible, to remove the defect in question altogether. 



STEAM AXD FIRE REGULATORS. 



Steam and fire regulatoi-s much resemble a safety valve. They consist 

 of a long lever, to which a weight is attached. This lever is acted upon near 

 its fulcrum by a large valve placed under it, which may rise and fall a small 

 distance without letting steam out, as is the case for a piston in a cylinder. 

 The end of the lever is united by a slender rod to the crank of a damper, or 

 of a valve in the chimney. "When the pressure of steam increases in the 

 boiler, the valve rises, the lever docs the same, and closes the damper; when 

 the pressure decreases, the valve comes down and opens the damper. The 

 weight on the lever is movable, and may be adjusted for any degree of pres- 

 sure. 



At the recent exhibition of the American Institute, in Xcw York, an un- 

 usual number of these contrivances were exhibited, the principal of which we 

 shall briefly describe. 



