AN ENCYCLOPEDIA OF HORTICULTURE. 



117 



Keating continued. 



Another modification of a saddle boiler is the Cruci- 

 form (see Fig. 174). It combines great Heating power 

 with economy of fuel ; the formation of its flues, in the 



FIG. 174. CRUCIFORM SADDLE BOILER. 

 a, Flow Pipe ; 6, 6, Return Pipes; c, c, c, Triangular Flues. 



shape of a cross, being such as conduces to a free circu- 

 lation of water, without the disadvantage of resting-places 

 being in them for sediment. Approximate Heating 

 power is much the same as in the Gold Medal Boiler. 



The Climax is a wrought-iron saddle boiler, somewhat 

 like the Gold Medal, but having only two chambers in 

 the interior, instead of three. It has a waterway both 

 at back and front, and is fed from the top instead of the 

 furnace door. This latter arrangement has now been 

 introduced into other forms of saddle boilers, it being 

 considered advantageous in saving labour in stoking. 

 There are various other modifications of the saddle in 

 use, where more chambers are made in the crown part 

 or on the sides. Those already noticed will be found 

 thoroughly efficient, and, not being complicated in con- 

 struction, are much to be preferred. 



A powerful boiler for Heating great lengths of piping, 

 on account of its form being specially adapted for sus- 

 taining heavy pressure, ia the Improved Cornish or 



Fio. 175. IMPROVED CORNISH OK XKENTIIAM BOILER. 



a, Flow Pipe ; b, Return Pipe ; c, Furnace Door ; d, Upper 

 Flue Door ; , Lower Flue Door and Front Stand ; /, 

 Back Stand. 



Trentham Boiler, represented in Fig. 175. It consists of 

 two wrought-iron cylinders, strongly riveted together, 

 about 2in. of water space being allowed between them. 

 The door frame is attached to one end, and the fire 

 bars are inside the cylinder near the bottom, which 

 forms an ash-pit, the upper, or larger, portion being the 

 furnace. In fixing, the boiler is stood on two cast-iron 

 stands, the front one forming a frame for the lower flue 

 doors. Walls are built clear of the boiler on either side, 

 and upper and lower flues formed by a course of fire 

 bricks being fixed against the side of the cylinder about 

 half-way up ; an arch spanning the top from this. The 

 heat is conducted through the centre, over the top by 

 the upper flue, and then returns by the bottom one to 



Heating continued. 



the chimney, thus exposing the fullest possible amount 

 of water space to the action of the fire. The minimum 

 approximate Heating power of this boiler, 5Jft. long by 

 3ft. diameter, is given as 2000ft. of 4in. piping; and 

 one 8ft. long by 3fcft. diameter is calculated to heat 

 5500ft. of the same sized pipes. 



Tubular boilers are composed of a series of cast-iron 

 tubes placed either in an upright or a horizontal direction, 

 and connected together for the free circulation of water in 

 all parts. Some are cast in one piece an objectionable 

 system, as any defect in casting, or an accident, may cause 

 a leakage at any time, which, if serious, would render the 

 whole useless. To meet this objection, and effect further 

 improvements, Messrs. Weeks and Co., of Chelsea, have 

 provided, in their notable and widely-used Duplex Upright 

 tubular boilers with diaphragm, a system by which the 

 whole may be worked together, or, in the event of an acci- 

 dent to one part, that half of the boiler may be removed 

 and the other still kept working until repairs are finished. 

 Duplicate parts are kept for replacing those which be- 

 come defective, without the necessity of substituting a 

 new boiler. Water tubes inclose the furnace, and small 

 horizontal ones are placed as fire bars. The fuel is 

 admitted at a circular hole in the top, which is provided 

 with an iron cover. Rivers' Patent is a rather expen- 

 sive, but a powerful, tubular boiler, which may be prac- 

 tically termed indestructible. It has a double row of 

 horizontal tubes, forming a semicircle above the fire, 

 which is fed from the furnace door. On any one of 

 the tubes becoming defective, it can be replaced by a 

 duplicate in a very short time, and the Heating con- 

 ducted as before. These boilers are in use, in some in- 

 stances, where enormous lengths of pipes are connected ; 

 but it should be stated that they have not been sufficiently 

 tried to prove whether they would be equally satisfactory 

 in all cases. They are noted for rapid circulation. 



C 



FIG. 176. UPRIGHT CYLINDER BOILER. FRONT ELEVATION. 



For Heating a small or moderate-sized house, such as 

 those frequently possessed by amateurs, a portable Upright 

 Cylinder Boiler and Furnace, similar to that shown in 

 Figs. 176 and 177, is well suited. It may be placed near 



