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Transactions of the Horticultural Society. 



can be ascertained from it, it is necessary to perform an ex- 

 periment, which, with the most practised hands, occupies 

 several minutes, and in the course of the year must consume 

 a good deal of ether. We repeat, therefore, that by keeping a 

 well watered floor, the affair of moisture may be left to nature. 



Atkinson's Melon-pits. (Jig. 60.) " These have been found far superior 

 to any other yet constructed. The principle is that of a brick pit heated 



by dung, and consists of four external walls, of which the back and sides 

 are four inches thick, and built in the pigeon-hole manner, (a) The front 

 is a hollow fourteen inch wall, open at top within side (b), and externally 

 formed with thin bricks set on edge in cement, (c) Against these walls 

 the dung is applied as usual, by which means dry heated air is communi- 

 cated to the pit from the front, and the damp warmth from the steam of 

 the dung penetrates the pit at the back and sides. This contrivance is 

 simple, and free from the objectionable points in M'Phails's pits, especially 

 in being much less expensive, and more roomy." 



We certainly think this the very best plan for pits to be 

 heated by dung that has yet been invented. For ordinary 

 purposes it may be made from five to seven feet wide, and 

 for fruiting pines from six to twelve feet wide, with plugs of the 

 size of brick-bats in the outer front wall(c), for the purpose of 

 being opened occasionally to admit steam from the dung. If at 

 any time the air in the pit was found not to be sufficiently 

 moist, the defect might be supplied by pouring w r ater into 

 the vacuity between the two front walls (b), from whence it 

 would be evaporated by the heated air, according as it was 

 more or less dry. The pits in the garden at Chiswick 

 are, for the most part, sunk in the ground, and the dung 

 linings covered with sloping wooden lids, which might or 

 might not be hinged (d); these coverings retain heat, 

 throw off the rain, and have a neat appearance. The 

 vacuity in the inside might also have a hinged covering (e), 



