ATMOSPHERIC HEAT OF VINERY. 5 



top ventilation, it is much more expensive than fig. 3, 

 which, for practical purposes, is equally good, the only 

 difference being the more finished and sprightly appear- 

 ance of the former as compared with the latter. 



ATMOSPHERIC HEAT OF VINERY. 



At the present day there is no question that the best 

 means for supplying this is hot water in pipes 4 inches 

 diameter. And let me here guard against the mistaken 

 economy which is so often practised, of fixing too 

 limited an extent of radiating surface to throw off a 

 given amount of heat. This leads to the constant stir- 

 ring of the fire to keep the water in the pipes as near 

 the boiling point as possible, entailing a far greater 

 expenditure of fuel than if there were a third more 

 pipe in the house. And it is well known to gardeners 

 that a given heat from a moderately heated surface 

 is more congenial to vegetation than the same heat 

 derived from a more limited but highly heated surface. 

 My own experience goes to prove that, in a vinery where 

 grapes are expected to be ripe in March or April, there 

 should not be less than one superficial foot of radiating 

 surface for every 16 cubic feet of air the house contains. 

 One foot in length of 4-inch pipe presents about one 

 superficial foot of radiating surface. This would be 

 something like four rows of pipe round front and ends 

 of a vinery 13 feet high at back, 2 feet in front, and 13 

 feet in width, which is the dimensions of the early 

 vineries at Dalkeith Palace, where a steaming-tray and 

 ventilator, as shown in figs. 4 and 5, are also used. The 

 tray is admirably adapted for supplying moisture to the 



