Heating Apparatus 



233 



Fig. 173." Saddle " Boiler with Waterway End 



one boiler, and this gives the advantage of two flows and two returns, 

 which can be made independent of each other if necessary. 



The " saddle " boiler is still very popular amongst all classes of growers, 

 especially amongst the " smaller " 

 men who cannot at first, perhaps, 

 afford to instal the dearer kinds. 

 The plain "saddle" boiler, which 

 has an opening right through, still 

 does serviceable work, but when- 

 ever possible it is replaced by the 

 type having a check or waterway 

 end (fig. ITS). There are many 

 types of these saddle boilers on the 

 market, one of the flued type being shown in figs. 174, 175, in elevation 

 and section. It is known as the Gold Medal boiler, and is made of wrought 



O 



iron. The heat from the fire (6) strikes the waterway end (e) before 

 ascending into the centre flue (c), whence it is deflected into the flues right 

 and left (d), and then goes over 

 the top of the boiler. In the 

 figures the ashpit is shown at a, 

 the flow pipe at k, the return 

 pipes at i, the sliding doors for 

 cleaning out the flues at /, and 

 the draw-off cocks at g. These 

 are useful when it is intended to 

 clear the water out of the boiler. 

 At I the hollow space is shown 

 round the boiler to utilize the 

 heat given off from the surface. 

 In the improved Cornish or 

 Trentharn boiler, shown at fig. 176, 

 we have a circular or cylindrical 

 type, being a modification of the 

 Cornish steam boiler. The boiler 

 consists of wrought-iron cylinders 

 welded together, and is seated on 

 two iron chairs or supports as 

 shown at a a. The front chair 

 forms the frame for the lower 

 and upper flue doors, shown at 

 b b, by means of which the soot 

 can be easily removed. At the 

 bottom of the cylinder is a plug . c, which, when unscrewed, allows the 

 water and all accumulation of dirt in the boiler to escape when necessary. 

 The two furnace doors are shown, one open, at d, while e is the flow pipe 

 on top, near the back, and / the return pipe low down at the side towards 



Fig. 174. Gold Medal Boiler (elevation) 



Fig. 175. Gold Medal Boiler (longitudinal section) 



