182 



HEATING AS APPLIED IN HORTICULTUKE. 



for the grate and ash-pit, 1 5 inches square 

 by 1 2 inches high. A movable iron grate, 

 x, is placed inside of this space, the bot- 

 tom or floor of which is just 6 inches from 

 the bottom of the boiler. It stands on 

 four legs, y, and it has two front bars, 2 

 inches apart, the highest of which comes 

 to within 2 inches of the boiler. It has 

 no back to it or sides, and can be removed 

 at pleasure. Projecting 2 inches from it 

 to the front are four iron brackets, to rest 

 a couple of fire-bricks on when the front 

 is to be closed ; b b is the neck of the 

 furnace. It is 10 inches square ; it is 16 

 inches from where the furnace begins to 

 incline inwards, at each of its four faces ; 

 it is 18 inches from the opening for the 

 grate ; and exactly 24 inches from the 

 floor of the grate, x, upon which the fuel 

 rests. Below this there is the ash-pit, 6 

 inches, making 2 feet 6 inches ; the lower 

 portion of which, for 14 inches up, is a 

 square of 15 inches, from which it gradu- 

 ally diminishes at each of its four faces to 

 10 inches at its neck. The front line of 

 this neck is about 4^ inches inside the 

 feeding mouth at c ; c c the feeding mouth 

 for putting in the fuel. It is 15 inches 

 broad by 12 inches high, having a tight- 

 fitting door e e ; d d is the farther end of 

 the boiler and the commencement of the 

 flue. It is 10 inches square, and 24 

 inches from the back line of the neck^>f 

 the furnace b b ; e e is the door. It has 

 its top and sides inclined to fit the shape 

 of the boiler completely when pushed in 

 close. The lower line is horizontal : / is 

 the blower to regulate the draught. It is 

 very simple, but may give place to a more 

 scientific method, if desired, although it 

 would be quite as effectual in practice as 

 any now in use, and much more simple. 

 It has four holes g near its top, to hang on 

 two hooks in the boiler. By using either 

 of these holes, the space below for the 

 admission of air to the under side of x is 

 enlarged or diminished; h are the two 

 fire-bricks which rest on the four brackets 

 from oc, and should fill up the space ex- 

 actly before the fire-bars to the boiler j k. 

 The flow-pipe j is just over the furnace ; 

 k is the return-pipe. These pipes, and 

 also those proceeding from them through 

 the houses, are square, 4 inches in dia- 

 meter, and will therefore expose," accord- 

 ing to the author's opinion, "one-third 

 more radiating surface than round pipes 



of the same diameter, and of course re- 

 quire one-third less piping to do the same 

 work. These pipes are both fixed to the 

 top of the boiler, the only difference being 

 that the pipe j has the advantage of being 

 just over the source of heat ; I is the 

 commencement of the flue, 10 inches 

 diameter. To derive all the advantage of 

 the fuel consumed, the flue should always 

 pass through one or all the houses. In 

 'the Captain,' less heat will escape by 

 the flue than with other boilers, because 

 the heat from the furnace will strike di- 

 rectly under the flow-pipe, and then it 

 must pass through the boiler 2 feet more 

 before it reaches the flue. It will pass 

 chiefly along the upper surface directly 

 under the pipes, which surface is pur- 

 posely made descending, thereby detain- 

 ing the heat as long as possible inside 

 the boiler, as heat descends with difficulty. 

 Notwithstanding the advantages of this 

 arrangement, there will always an im- 

 mense quantity of heat pass into the flue, 

 as soon as the fuel has become ignited 

 throughout, which will generally be to- 

 wards morning, when it is least desirable 

 to throw the heat away. To save this," 

 the author " has shown how the flue is to 

 be brought inside the house without the 

 possibility of damage ; m is a thin metal 

 trough, 12 inches square, open at top : 

 the flue (also of thin metal) passes through 

 this, being clear of it all round. This 

 trough is to be partly or wholly filled 

 with water as required, and a cover of 

 some kind, w, or even a roll of coarse can- 

 vass, to be used when wanted. The trough 

 should be a little clear of the floor, in 

 order that the heat may be given out 

 from all its faces. If this flue be made 

 quite straight through the houses, the 

 cleansing of it out (it not being intended 

 to return, the chimney being placed at the 

 far end) will be a very easy matter. From 

 ntoo the height of the boiler is 3 feet 10 

 inches ; from o to p its length is 3 feet 

 2J inches ; from n to q its breadth is 19 

 inches. The space all round the boiler, and 

 at top and bottom, for water, is generally 

 2 inches only, except where the sides and 

 top of the furnace slope in, when it be- 

 comes rather more. It is not in the boiler- 

 house that a large quantity of heated water 

 is wanted ; r r r r is a space of 3 inches 

 all over and around the boiler in every 

 direction, except under it, (and it may be 



