PITS HEATED BY HOT WATER, &c. 



455 



tically, communicating with the chamber 

 below, and provided with proper stoppers 

 to allow heat to ascend into the atmo- 

 sphere of the pits. These may be placed 

 in two rows along the pit, at the distance 

 of 6 feet apart, as the heat passing 

 through their sides, even when their ori- 

 fices are stopped, would greatly tend to 

 heat the soil in the beds, and not materially 

 interfere with the roots of the plants. 



The pits should be provided with port- 

 able rafters and glazed sashes, on the 

 span-roofed principle, leaving the wall- 

 plates, which should be of cast-iron, to 

 remain permanently on the walls for their 

 protection. Wooden shutters are nearly 

 now as expensive as glass sashes. The 

 advantages of the latter over the former 

 are very great ; and it is the more advis- 

 able that these should be used, as they 

 w T ould only be required for that set of 

 pits which was to be forced during the 

 current season ; and as that season is of 

 short duration, they could be usefully 

 employed for other purposes. We think 

 that, by such a mode of heating, a more 

 certain result might be expected ; and as 

 the water, after the forcing season had 

 passed, could be withdrawn, by allowing 

 the boiler to discharge itself into a drain, 

 the pipes would last for years in a work- 

 ing state. The depth of soil we would 

 allow for the roots of the asparagus would 

 be 2 feet ; but that should be of the most 

 fertile description possible, aided, during 

 the growing season, by copious waterings 

 of highly enriched liquid manure. 



Trentham melon and pine pits, fig. 640. — 

 Pits upon the principle here exhibited 



exist to a large extent in the gardens at 

 Trentham, and, under the very judicious 

 management of their inventor, Mr Flem- 

 ing, have been found admirably suited to 

 the culture of both melons and pines. 

 Atmospheric heat is secured by a 4-inch 

 hot-water pipe, which traverses the whole 



length at the level g, returning along 

 the front at h, when it descends below 

 the level of the soil, and makes a second 

 circuit through the pipes a a. These 

 latter pipes are embedded in a mass 

 of stones b b, and rough gravel, which 

 abstract the heat from the pipes, and 

 diffuse it through a bed of leaves d, over 

 which the soil e for the plants to grow in 

 is placed. When melons are grown, the 

 trellis / is used ; when pines are planted 

 out, this trellis is dispensed with. Mr 

 Fleming prefers hot-water pipes for bot- 

 tom heat to either tanks or open gutters : 

 the latter, he thinks, tends to render the 

 soil much too damp for healthy vegeta- 

 tion; and he depends upon surface- 

 watering for keeping the mould in a 

 proper state of humidity. These pits 

 recommend themselves on account of 

 their simplicity and economy, not only 

 in their first erection, but in working 

 them afterwards ; and if we are to 

 measure their fitness for the purpose 

 intended by the extraordinary success 

 which has been exemplified at Trentham 

 as regards the culture of both pines and 

 melons in them, then would we say that 

 such pits rank amongst the very best of 

 their kind. By the use of such pits we 

 at once get rid of the greatest nuisance 

 that can exist in a garden, as well as pre- 

 vent an unnecessary waste of fertilising 

 material in the shape of stable manure. 



Glendinning 's melon-pit, fig. 641. The 

 intelligent designer of this pit was im- 



pressed with the idea that melon culture 

 was long defective, in so far as there were 

 difficulties in supplying moisture to the 

 bottom of the beds, particularly those 

 heated by hot water, whether in close 

 pipes or open tanks. In the annexed 

 sketch, " the gutters of water are confined 

 in the chamber beneath ; and when steam 

 is required in the pit, valves are provided 

 at a, by which it is allowed to escape into 

 the pit amongst the plants. The soil 



