CH. I.] WALL-TREES. 25! 



fmooth, and pafs the roller over ; then, the 

 fame quantity of clean pit or river gravel, 

 which alfo gently fettle with the roller j 

 over this, lay a fecond courfe of loam, to 

 the depth of an inch only, and likewife 

 pafs the roller over it. All this muft be 

 done while the materials are in a pretty 

 dry ftate. But now the whole is to be 

 made a little moift, and rolled till the fur- 

 face becomes glazed ; after which, water 

 and roll alternately till it acquires a hard, 

 mining confiftency, and the gravel is in a 

 considerable degree appearing through the 

 loam. 



Thus will a bottom be formed, which 

 no roots will penetrate, of a more kindly 

 nature, and at a much lefs expence, than 

 brick or ftone. 



The fitteft compofition for apricots, ap- 

 ples, cherries, and figs, is -three-fourths 

 light fandy loam, and one-fourth ftrong 

 clayey loam, mixed with a competent quan- 

 tity of ftable-dung, cow-dung, and marl, 

 in compoft ; the apricots and figs requiring 

 confiderably more dung than the apples 

 and cherries. For pears and plums three- 

 fourths 



