8o MY GARDEN. 



the pipes with a cistern of water. The warm water rises immediately 

 to the top of the cistern and the cold water passes to the stove. This 

 latter method, I believe, originated in my garden, and for the growth 

 of orchids and pine-apples should exclude other plans. 



Two boilers are at work with me, one a saddle boiler heating the 

 fernery with three hundred feet of 4-inch pipes, the cutting-house with a 

 tank holding about two hundred gallons of water, and the Poor Man's 

 House with about a hundred feet of 3-inch pipes. The second boiler 

 heats the cucumber-house with a tank holding about two hundred 

 gallons, and the grapery is heated with about two hundred feet of 

 three 4-inch pipes* and a small pine-pit with about forty feet of 

 4-inch pipes. 



During last summer a portable boiler has been employed to heat 

 a tank for a melon-pit (fig. 96), where the mould (M) is placed on 



FIG. 96. Tank Pit. 



boards (B) over the tank (T), and a current of air is allowed to play 

 over the water into a chamber, from whence it rises to warm the 

 upper part of the pit covered with the light (L). 



In the arrangement of pipes it is usual for the water to flow along 

 the top pipe and return by a lower pipe, as represented at fig. 94. 

 It has been proposed, however, to make the water flow by the lower 

 pipe, then through the higher, and rapidly descend to the bottom of 

 the boiler (fig. 97). This plan has been recorded as in use at Deptford, 

 and assuredly would be adopted by me, but that it is difficult to sink 

 the fireplaces sufficiently low at my garden. 



At my pine-pit it is necessary to cause the water to circulate 

 below the level of the boiler. This is effected by causing the water 

 to flow into an open pipe, and then turn .down to the desired level 



