226 VENTILATION BY DRAINS. 



believe, of the celebrated George StephenBon, effected thus the ventila- 

 tioa of a vinery heated by hot-water. Underground drains were sunk, 

 3 feet deep, at right angles to the front wall, and extending from its 

 inside to a walk about 12 feet distant from the house, and parallel with 

 it. At each end of the drains was a perpendicular shaft ; that in the 

 inside opened immediately behind and below the hot-water pipes, and 

 was never closed ; that in the open air was closed by a moveable square 

 plug. So long as the plug remained in its place no ventilation took 

 place. As soon as the plug was removed, the denser external air 

 pressed down into the shaft, and, rushing through the drain, delivered 

 itself among the hot- water pipes, expanding rapidly in the house, and 

 dispersing itself among the plants. The drains being always damp, on 

 account of their depth in the moist heavy clay of Drayton Manor, the 

 air which passed through them was always charged with as much 

 moisture as was required. When the author saw this apparatus at 

 work, some yfears since, its action was all that could be desired ; and 

 it would appear, from the following communication, made to the 

 OardenerS Chronicle, of January 28, 1854, that the merit of the plan is 

 recognised in the neighbourhood : — " I beg to add my testimony to the 

 advantages of underground drains for admitting air constantly to plants, 

 especially in such weather as we have lately had, when other means of 

 aeration must have been but limited. The plan adopted here is 

 different from that at Drayton Manor ; one large pipe is laid 3 feet 

 deep, beginning at 90 feet from the front flues ; it is carried to within 

 15 feet of the intended openings in the house, where three small pipes 

 are cemented with their ends inside the larger one, one giving air in 

 the middle of the house, the two others at equal distances on either 

 side. It was inconvenient to bring the drain in front of the house, 

 consequently it begins at the back, and is carried under the floor of the 

 potting-shed and the house itself to the front flues. Besides the advan- 

 tage of furnishing air at all times, the drains materially assist in 

 keeping out frost; taking, for instance, the morning of January 3, 

 when the thermometer was at 4°, I firmly believe that the plants Would 

 have been frozen, had it not been for the air admitted at the tempera- 

 ture of the earth three feet deep. I should prefer the plan employed at 

 Drayton Manor, where the drains are in front, and each drain entire 

 throughout. The late Mr. Milne (once gardener at Drayton) told me 

 that the drains exceeded his most sanguine expectations, as indeed the 

 health of his plants abundantly testified. I should mention that the 

 heating apparatus in the house above alluded to is very small — quite 

 insufficient for such extreme cold as that on tiie night of January 2. 

 On stopping the drains on cold nights, the temperature of the house has 

 been lower than on similar nights when the drains have been open, 

 the external temperature in both cases being the same. — T, Dowell, 

 . Amington Hall." 



