PITS. 



21 



4 



PITS. 



with a tubular or pipe -like termina- 

 tion. Some florists then cut off the 

 tips of the leaves, but others leave 

 them entire, as shown in fig. 23, and 

 in both cases the pipings must be struck 



FIG. 23. f 



PIPING OF A CARNATION. 



in sand "with a hand-glass fixed firmly 

 over them. It may be here observed, 

 that the herbage of Pinks and Carna- 

 tions is called the grass ; and that 

 when a plant is in a vigorous state of 

 growth, it is said to have the grass 

 fine. 



Piptanthus. — Lec/uminosce. — A 

 handsome half-hardy tree with large 

 yellow pea-flowers. It will grow in 

 any common soil, but it requires a 

 slight protection during winter. 



Pista'cia. — Terebinthacece. — The 

 Pistaccia Nut tree. Very handsome 

 trees, which abound in turpentine in 

 their native country, but which are 

 only half-hardy in England. 



Pits are structures either sunk in 

 the ground, or raised above it with 

 brick walls on all sides, and with a 

 glass cover. For the purpose of pre- 

 serving plants from the frost, they do 



not require flues, beds of tan or dung, 

 or any other artificial mode of heating ; 

 but they do require artificial heat 

 when they are employed for preserv- 

 ing greenhouse plants, for growing 

 hothouse plants, or for forcing hardy 

 herbaceous flowers or shrubs into pre- 

 mature bloom. They are also used 

 as a substitute for hotbeds in bring- 

 ing forward tender annuals, and in 

 raising seeds. For all these purposes 

 some mode of artificial heating is re- 

 quired ; and this may either be accom- 

 plished by smoke-flues, the circula- 

 tion of hot water in pipes of iron or 

 earthenware, or by the introduction 

 of beds of fermenting materials, such 

 as tan or dung. The most conve- 

 nient mode of heating is unquestion- 

 ably by hot water, because by this 

 mode there is less danger of produ- 

 cing excessive heat ; and the heal 

 from being accompanied by moisture, 

 is more congenial to vegetation than 

 the dry heat of smoke flues. Where 

 hot-water pipes cannot be conveniently 

 procured, or in the given locality are 

 more expensive than smoke-flues, 

 then these may be adopted ; taking 

 care to supply moisture to the at- 

 mosphere of the pit by placing pans 

 of water on the flues ; or by keeping 

 the surface of the soil, or the path, if 

 there be one, moist by the supply of 

 water from time to time. The con- 

 struction and the heating of pits are so 

 well known to gardeners, builders, 

 and ironmongers, that very little need 

 be said on the subject. They may 

 be of any convenient length — six feet, 

 eight feet or ten feet in width, three 

 feet high above the surface of the 

 ground behind, and of such a height 

 in front as that the slope of the glass 

 may form an angle with the horizon 

 of between 20° and 30°. The depth 

 to which the pit is sunk in the soil 

 will depend on the uses to which it is 

 to be applied. When it is merely to 

 preserve plants from the frost of 



