98 



IMPROVEMENT OF A COMMON FIRE-PLACE. 



When thus heated, the air is carried in 

 straight tubes through the water in the 

 boiler, entering at the back, and passing 

 off in front. Being unmixed with the 

 smoke, it does not soil the tubes, which, 

 therefore, rapidly transmit the heat ; and 

 the air in its pass-age is effectually cooled 

 down to the heat of water. In this state 

 it is conducted under the ash-pit, thus 

 feeding the fire with air at the heat of 

 212 degrees, from which, as repeated 

 analyses have shown that it has parted 

 with little or none of its oxygen, important 

 benefits arise; the fire is saved the neces- 

 sity of heating up to that degree the 

 whole air which passes through it, and 

 the process of combustion is otherwise 

 beneficially promoted. The ash-pit is 

 closed with doors, and the draught of the 

 chimney establishes and keeps up the re- 

 quisite current of air for the purpose of 

 combustion through the heating trough, 

 the cooling tubes, the fire, and the flues. 

 The additional heating surface thus gained 

 by the tubes in the boiler, exceeds the 

 fire surface, or bottom of the boiler, by 

 fully one-half — The saving of fuel com- 

 pared with the ordinary furnace and boiler 

 is estimated at 33 per cent. 



The diminution of the boiler also tends 

 to add to its strength ; and the increased 

 facility in transmitting to the water, the 

 heat derived from the fire, arising from 

 the greater heating surface afforded by the 

 tubes, must still further operate to prevent 

 the imminent hazard arising in marine 

 boilers, from the exertions of the engine 

 men to generate steam more rapidly. By 

 the intensity of the heat thus produced, 

 many parts of the boiler and flues, especi- 

 ally those where incrustations have been 

 formed on the bottom, or where the 

 water spaces have been too much con- 

 tracted, become over-heated and con- 

 sequently weakened and ultimately des- 

 troyed. Whatever tends safely to ac- 

 celerate and facilitate the transmission 

 of the heat to the water, obviously 

 diminishes the necessity to contract the 

 water spaces, and the temptation to force 

 the fire. It is also important that the 

 heat which is absorbed by the air, is 

 withdrawn from the fire, at the point at 

 which it is fiercest, and is by a proper 

 distribution of the tubes, applied to the 



portions of the water farthest removed 

 from the direct influence of the fire. If 

 it shall be found, as we have reason to 

 expect, that hot-air used in the furnace 

 will enable anthracite coal to be burned, it 

 is not easy to see to what extent of saving \ 

 this discovery may lead in steam naviga- 

 tion; this coal being vastly more powerful 

 than any other. It is no small advantage 

 to the public, and no slight recommenda- 

 tion of this plan, that not only does it not 

 interfere with any other improvements 

 for economy of fuel now in use, but it is 

 rather an addition to, and may be used 

 in conjunction with them, and also that 

 it may be easily adapted to almost any 

 existing furnaces, boilers, and processes 

 of manufacture, at an expense altogether 

 trifling, contrasted with the benefitresult- 

 ing from its use. — Mining Journal. 



IMPROVEMENT OF A COMMON FIRE-PLACE. 

 BY M. SAUL, 



Upon the grate is fixed a cast-iron plate 

 with a circular aperture in the centre. It 

 is 82 inches in diameter, which just takes 

 a common tea-kettle, and answers well 

 for other sized pans, as I find it is of no 

 moment, the pan being larger than the 

 aperture. By this plan the heat is con- 

 fined in the grate; and by several experi- 

 ments I have proved that any thing will 

 much sooner boil in this closed grate, than 

 in an open one, and it also throws out a 

 greater heat in the room and prevents 

 smoke ; and when the fire is not wanted 

 for cooking, there is a plate to cover the 

 aperture. It also consumes less fuel, and 

 is a sure remedy for a smoky chimnt^y. 

 The whole heat may be made to act on 

 an oven placed at one side of the fire by- 

 turning a damper in the flue. A small 

 hole is made in the top of the plate, to 

 admit any smoke that may arise when 

 putting on fuel, or changing kettles or 

 pans. The top plate rests on the top bar 

 of the grate and on the brick work at the 

 back, and another plate in front. 



Jirek Mag. 



IMPORTANT TO FARMERS. 



It may not be generally known to our 

 agricultural readers, that the vegetative 

 powers of wheat are greatly increased by 



