234 VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 



to the chamber, and the border for maintaining a perceptible 

 warmth in the latter for twelve or fourteen hours. A division 

 is made in the tank for the circulation and displacement of the 

 water, as shown by the arrows in Fig. 49. Pigeon-hole walls 

 are built across the border, about five feet distant from each 

 other. Upon these rough pieces of timber are laid, as a bottom 

 to the border ; a layer of brush-wood (small branches) is laid 

 over the timber to prevent the soil from falling through upon the 

 tank. The rest should be filled, to the depth of two feet, with a 

 good turfy material, with a plentiful admixture of whole bones 

 and rough pieces of charcoal, to render the mass as porous as 

 possible, for the admission of the heat upwards, as well as to 

 maintain an equality in the moisture of the mass. Shutters are 

 provided for covering the border, which may lie upon the same 

 angle as the roof, or otherwise, as the front wall of the house 

 corresponds to the curb in front of the border. Ventilators are 

 placed in the front wall, beneath each light, for the admission 

 of air into the house ; and when air is required by these front 

 ventilators, the shutters covering the border must be tilted at 

 the lower side, when the air passes across the border, through 

 the front, into the house. We consider this mode of arrange- 

 ment for the border cheaper and better than that of arching the 

 chamber, as shown in Fig. 48, although both are equally effect- 

 ual, and may be adopted as circumstances may suggest. 



If chambered borders be found so beneficial in England, for 

 winter forcing, where the frost seldom penetrates more than a 

 few inches into the ground, and rarely continues for more than 

 a few days at a time, a week or two, at the longest, surely 

 it must prove equally if not more serviceable in the New Eng- 

 land states, where the winters are so intensely cold as to render 

 the forcing of grape-vines at that time next to impossible. Still, 

 if the forcing of this fruit can be carried on at mid-winter, at a 

 reasonable cost, there is no reason to suppose that it would be 

 unprofitable, even at the low prices at which grapes are usually 

 sold in the principal markets of this country. All cultivators 

 are aware that the profits of fruit culture are just in proportion 

 to the economy with which good crops can be produced ; and 

 this is more especially the case in the culture of exotic fruits, 



