HEATING BY HOT-AIR STOVES. 



221 



the chief portion of the chamber, stand- 

 ing isolated within it, except at the points 

 where the fuel is supplied and the ashes 

 removed, and where the return-flue passes 

 into the chimney. The area left between 

 the wall of the stove and the wall of the 

 chamber is 2 inches, except on the side 

 next the hothouse, where there is a larger 

 area to allow the cold air to rise and flow 

 over the plate ; but it will probably," 

 Mr Meek thinks, " be found desirable to 

 sink the top of the stove to a level with 

 the cold-air drain. The stove is formed 

 of four walls of 9 -inch brickwork ; the 

 outside measure is 5 feet 5 inches long, 

 4 feet 4 inches wide ; the internal mea- 

 sure, therefore, 3 feet 10 inches long, and 



2 feet 10 inches wide. Another wall of 

 the same substance is carried up between 

 the two ends, but not in the centre ; it is 

 16 inches from the wall of the stove next 

 the hothouse, leaving a space of 9 inches 

 between itself and the farther wall. It 

 will be seen by the plan, that this wall, 

 and the one next the hothouse, form the 

 actual furnace or fuel-box. In part of 

 their length, where such is the case, they 

 are built of fire-bricks, as are also the 

 flues ; and wherever the walls are likely 

 to be much heated, they are Stourbridge 

 lire-bricks, set in the same clay, being," 

 in Mr Meek's opinion, "more durable 

 than Welsh lumps. It will be well to 

 parge the outside of the walls of the stove. 

 The stove is 3 feet high, which allows 



3 inches for paving of ash-pit x 1 foot for 

 depth of ash-pit x 3 inches for depth of 

 bars x 1 foot 6 inches for depth of fur- 

 nace from bars to plating = 3 feet. The 

 iron top is formed of three plates, with a 

 view to allow for expansion. Two of these 

 plates have extended rebates. They are 1 

 foot 6 inches one way, by 3 feet 6 inches 

 the other ; so that, when laid in their place, 

 and the space for expansion between each 

 allowed, they form a surface of 4 feet 7 

 inches by 3 feet 6 inches. This, by calcula- 

 tion, will be found to give them a 4-inch 

 bearing on the four outside walls of the 

 stove. Along the wall of the stove next the 

 hothouse, a course of thin brick is laid, not 

 close to the edge of the plating, but half an 

 inch from it. The two end walls are carried 

 up three courses higher in 4^-inch work ; 

 and so is also the outer wall ; and between 

 all these and the edge of plating there is 

 a | -inch space. The purpose of this groove 



exhalation. 



Fig. 300. 



is to fill it with sand, so that the plates 

 can expand and squeeze up the sand, 

 while, when they contract, this will fall 

 back and keep the joint air-tight. I am 

 assured, however," says Mr Meek, "by 

 practical men of great experience, that it 

 will be found quite unnecessary to have 

 the plates cast in three pieces ; that it will 

 suffice if cast in one piece, provided it were 

 cast with a loop round the edge, which 

 should fall into a groove of sand, and that 

 the plate would then expand in the loops : 

 this will greatly lessen the danger of 

 The situation, as shown in 

 the section fig. 300, 

 of the damper b, is 

 bad. It should be 

 placed exactly at the 

 junction of the flue 

 with the chimney; and 

 it will be found to 

 economise fuel, by pre- 

 venting the loss of 

 heat, if between the 

 brickwork forming the end of the cham- 

 ber and the stove some non-conducting 

 material, such as hair felt, be placed, and 

 also if double doors be used for the fur- 

 nace. I find the only loss of heat that 

 takes place in the apparatus is from the 

 furnace doors and the brick around them, 

 and this might be prevented by the above 

 plan. The doors employed are Sylves- 

 ter's patent, which, for all purposes where 

 the regulation of draught is required, 

 seem to be the best that can be imagined. 

 There are no hinges to rust, or machinery 

 to get out of order, or screws to untwist: 

 they simply hang on a frame, in which 

 they slide, the edges of the door and 

 frame being ground to fit. And another 

 advantage which they possess is, that if 

 any explosion should take place within 

 the stove from a collection of gases, (and 

 all economic stoves, where, of course, the 

 combustion is slow, are liable to such 

 occasionally,) instead of the boiler or 

 plates being blown out of their place, 

 these doors would be lifted outwards, and 

 the evil consequences avoided. Within 

 the chamber extending between the two 

 end walls of the stove, and bearing slightly 

 on the end wall of the hothouse, is a tank 

 of water,/, divided longitudinally, 4 inches 

 deep, as shown in the section, also by 

 dotted lines in the ground-plan, supplied 

 by a check-cistern from the outside g, 



