140 



ON THE TANK SYSTEM OF HEATING 



which many other sorts will not do. I have six lights of them 

 planted on Mr. Hamilton's method, from which I have cut fine 

 fruit, and will continue to do so all through the winter. The 

 fruit swells much better than I ever could cause them to do in 

 pots. I have several just now (December) with two fine fruit 

 on one plant, of larger size than the first single* fruit cut from 

 the same plant. With respect to treatment, I manage them just 

 the same in every point as if they had been in pots, keeping 

 the atmosphere much dryer in winter, giving no water whatever 

 from November till February, with very little air, and we find 

 the fruit nearly, if not quite, equal in flavour to summer fruit, 

 the produce being double what we should have obtained from 

 plants grown in pots, as the fruit is much quicker in its growth 

 and the suckers are often ready to show fruit by the time others 

 on the plant are ripe. 



I have seen tanks erected at several places on different and, 

 what I consider, unnecessarily expensive plans ; but from the 

 experience I have had of the tanks erected here, I cannot see 

 that they can be improved upon, either in durability, economy, 

 or in most effectually answering the end in view. They are 

 gutters of cast-iron, eight inches wide and four inches deep ; the 

 pits are nine feet wide, and the gutters are carried along the 

 front and return by the back wall, at eighteen inches distance 

 from the wall all round, resting on bricks about ten inches from 

 the ground ; the floor is of flag-stone, about two inches in thick- 

 ness, and laid an inch clear above the tanks ; it is also supported 

 on brick piers, which are built as the floor is laid, without any 

 regular order, but just w r here wanted, to suit the joints and the 

 size of the flags. When the floor is laid the joints are carefully 

 filled with Roman cement. At certain distances, close to the 

 front wall, holes are chiseled through the floor two or three 

 inches square, on which pipe-tiles are fixed with cement : these 

 serve for chimneys, to admit the steam at pleasure amongst the 

 plants ; but when steam is not wanted a piece of slate is laid over 

 the top of the pipe, which effectually stops its escape. When 

 the floor is finished I lay on about six inches of broken bricks, 

 the largest pieces being laid on the bottom, a second size over 

 these, and over all are sifted the smallest-sized pieces, which are 

 not larger than hazel-nuts. These effectually prevent the fine 

 soil or dust from penetrating through the rubble, which, be- 

 sides acting as a drain for the soil above, serves as the grand 

 medium whereby the heat is equally distributed the whole length 

 and breadth of the pit, betwixt the floor and the soil. Over the 

 floor and rubble I next put a foot or more of fresh leaves, well 

 trodden down, which makes not only an excellent bed whereon 



