Oct.] THE HOT-HOUSE. 553 



day. It should be filled with fresh well prepared tan, to the depth 

 of three feet when settled, and the pots plunged therein to their 

 rims, the smallest sized plants in front, the largest towards the 

 back part. 



The frame should be entirely surrounded with a large quantity 

 of the fallen leaves of trees to its full height, having still more in 

 reserve to add, as the others sink and contract in bulk, in conse- 

 quence of fermentation and pressure, always keeping them full up 

 to the top of the frame on every side; the leaves will soon heat and 

 cause the tan to ferment, and between both a fine glow of warmth 

 will be kept up in the frame during the whole winter; this, with the 

 assistance of a suitable covering of mats, boards, &c. at night and 

 in severe weather, will keep the most tender plants in health and 

 good condition. 



Linings of hot horse-dung may be substituted in place of leaves, 

 but the latter is preferable on account of its slow, steady and long 

 continued heat. 



Oak Leaves used as a substitute for Tan. 



As oak leaves abound in almost every part of the United States, 

 it is of some importance to know that they may be used in forcing 

 pits of every kind, in place of tanner's bark, and with advantage, 

 their heat being constant, regular, and continuing for a long time, 

 often for an entire year; whereas bark generally turns cold soon 

 after its violent heat is gone off, which obliges the gardener to fork 

 it up frequently in order to revive the heat. 



The sooner the leaves are raked up after they fall from the trees 

 the better, as the quality and fermenting substance will naturally 

 decrease during the time they are exposed to the weather. 



When raked up they should be carried immediately into some 

 open shed, and there thrown into a heap to settle and ferment. — 

 In this place tread them well, and water them a little if you find 

 they are rather dry. The heap should be at least six or seven feet 

 in thickness, and covered with old mats, as well to promote a gene- 

 ral fermentation as to prevent the upper leaves from being blown 

 away by the wind. They should be suffered to remain in this state 

 for four or five weeks, by which time they will be properly pre- 

 pared for the pits, and will not settle down much after. In put- 

 ting them into the pits, if they appear dry, water them a little and 

 tread them in layers, exceedingly well, till the pits are quite full: 

 then cover the whole with tan to the thickness of two inches, and 

 tread it well till the surface becomes smooth and even. On this 

 place your pots of pines or other tender plants in the manner they 

 are to stand, filling up the spaces between them with tan as you 

 proceed, row by row. 



After this, the leaves require no farther trouble the whole season 

 through, as they will retain a constant and regular heat for twelve 

 months, without either Stirring or turning. 



Leaves mixed with stable (lung make excellent hot-beds, which 

 preserve their heat much longer than when made of dung only. 

 3 X 



