232 



Commercial Gardening 



Fig. 171. Rochford Horizontal Tubular Boiler 



Boilers. Of these there are many varieties on the market all sorts, 

 shapes, and sizes. Some of the older types, like the " wedge ", " coil ", 



and " conical ", have 

 been driven out al- 

 together, even from 

 private establish- 

 ments, having been 

 superseded by the 

 " saddle " (of various 

 designs), the upright 

 and horizontal "tubu- 

 lars ", the " Cornish " 

 or cylinder boiler. 

 And during recent 

 years the "sectional" 

 boilers largely used 

 on the Continent 

 and in America have 

 begun to find a footing amongst British growers. 



What the market grower and nurseryman aims at above all things is 

 to have a boiler that will not only wear well, but will generate the greatest 



amount of heat at the least expense 

 of coal or coke, or labour in stok- 

 ing. In addition to this, one that 

 can be repaired easily is a great 

 advantage. 



At the present day perhaps the 

 horizontal tubular boiler, as shown 

 in fig. 171, is the most popular with 

 large growers. The flues are in a 

 direct line to the smoke shaft, a 

 greater surface is exposed to the 

 fire and consequently heat is gener- 

 ated more quickly; and in the 

 event of a tube giving way a new 

 one can be substituted in a very 

 short time. A boiler of this de- 

 scription, 9 1 ft. long, is capable of 

 heating 2000 ft. run of 4-in. pipe, 

 the total cost for boiler and fittings 



Fig. 172. Weeks's Duplex Upright Tubular Boiler being about 20. 



The duplex upright tubular 



boiler as shown in fig. 172, although extensively used in private places, 

 is not so largely patronized by big market growers. This particular boiler 

 is made in two equal parts each of which can be worked independent of 

 the other in case of accident. As a rule the two sections are worked as 



