Furnishing and Regulating Heat, 65 



which escapes during the heating process is of great 

 benefit to the growing crops, while from other material 

 there is no such benefit — substantially nothing but 

 the heat is derived. 



Radishes require less heat than lettuce, just as a 

 crop of young cauliflower or cabbage requires less heat 

 than tomatoes, egg-plants, or others of a tropical nature. 

 For radishes, a cart-load of manure, containing thirty- 

 six feet, would be sufficient for nine feet of bed, or 

 three sashes, and should be covered by one foot of 

 loam. For forcing cucumbers more heat is required 

 than for lettuce, according to the season. In any case, 

 the bed should stand a day after it is prepared, to 

 allow the soil to heat through ; it is then ready for 

 seeds or plants. 



The quantity of heating material to be used will not 

 however depend entirely upon the crop to be grown ; 

 we must also take into account the season of the year 

 when it is to be started. With lettuce, for instance : if 

 the crop were to be planted in December, a foot of 

 fresh manure would be necessary ; while in February or 

 March one-half that quantity would be sufficient. But 

 for such tropical-natured plants as tomatoes, cucum- 

 bers, or egg-plants, a foot of heating material would be 

 none too much at any season. 



A crop of radishes would not perhaps require quite 

 as much heat as lettuce during the winter months ; 

 still it would need about the quantity stated to keep 

 the bed properly warm. If started in March, no strong 

 bottom heat w^ould be required ; and they will succeed 

 well on second heat, such as is in a bed from which a 



