SOT-BEDS AND PITS. 139 



For some little time after the bed is made, its heat will 

 be too great for vegetation ; four days after making, it 

 should be watered, closed up for another heating, and 

 watered again before spreading the mould on the sur- 

 face. When the bed has been in use some little time, 

 and the heat declines, it may be renewed by what gar- 

 deners call lining. This lining, by somewhat contrary 

 rule, is some heating material packed round outside the 

 bed. Fresh manure may be used, and gardeners often 

 use for the purpose the cuttings of the lawn : it should 

 be laid round the bed eighteen to twenty-four inches 

 thick. If the manure of the hot-bed be sunk, a trench 

 must be made to sink the lining to equal depth, that the 

 heat may be renewed throughout the whole mass. If a 

 second renewal of heat be required, this lining may be 

 removed, and a new one put. 



Tan or tanner's bark, as a source of heat, requires 

 frequent stirring and renewing. When the bark is 

 brought fresh from the lanyard it may be lightly thrown 

 together under cover, gently moistened, and turned over 

 twice a week. About four weeks in warm weather, or 

 five in colder, will suffice to make the fermentation 

 general and regular. It will keep its heat for several 

 months, and when the heat declines (it will do so some- 

 times without apparent cause) the tan must be sifted, 

 the dust removed, and fresh tan added. Sometimes 

 turning over and wetting the old tan will do. It is well 

 to mix old and new tan together to make a new tan bed, 

 the quantity of new must depend on its goodness, and 

 on the heat required. Two-thirds new and the rest old, 

 almost decayed to mould, should produce a bottom heat 

 of about 85. If the old tan used have heat left in it, a 

 smaller quantity of new may be added to make a new 

 bed, and the heat may be renewed afterwards with much 

 less. Forking up will answer the purpose between 

 whiles. Five-sevenths of the pit may be filled up with 

 the new and old tan in a state of fermentation, and the 

 remaining two-sevenths with old tan, without heat, in 

 which to sink the pots. 



Some facility for using artificial heat is almost a 



