146 Suggestiofis Joy the Improvement 



to the soil in which they grow, they have arrived at maturity, and, 

 indeed, have most of them begun to decay. 



2. A mode of deterring the scolytus will be found detailed in 

 the Arboretum Britannicum, p. 1 390., and in a future page of 

 this Magazine; but the best practical method, in our opinion, 

 to guard against this, or any other insect that attacks trees in 

 such a scene as Kensington Gardens, and to limit the extent of 

 their ravages where they have made an attack, is, to introduce a 

 number of different species of trees, natives of different countries 

 and climates; in short, to render the garden an arboretum; 

 avoiding, however, all trees not decidedly hardy and of vigorous 

 growth in the climate of London ; and all that require peat 

 earth, any soil difficult to procure, or any situation either very 

 moist or very dry. 



3. All the trees ought to be planted in pits of prepared soil. 

 These pits ought to be 4 ft. or 5 ft. deep, and not less than from 

 12 ft. to 16 ft. in diameter ; or to occupy from 16 to 20 superficial 

 yards of surface. The pits should neither be round nor square, 

 but star-shaped, or cross-shaped ; that is, eitlier of such a form 

 as would be produced by placing one equilaterjil triangle on an- 

 other, the points of one triangle being opposite the middle of 

 the sides of the other ; or as would be produced by placing two 

 parallelograms across each other at right angles, so as to form 

 a Greek cross. The object of departing from the square or 

 round form is, to introduce the growing fibres of the trees into 

 the firm and poor soil by degrees, and not all at once, as would 

 be the case were the pits made of square or circular forms, in 

 the usual manner. The trees, thus planted, would also be better 

 able to resist high winds, as they would take a firmer hold of the 

 soil. When a tree is planted in a round or square pit, dug in 

 hard bad soil, it is in much the same situation as if its roots 

 were confined in a pot or tub. The dovetailing, so to speak, of 

 the prepared soil and of the moisture which it will retain, with 

 the hard impenetrable soil by which it is surrounded, will gra- 

 dually prepare the latter for being penetrated by the roots of the 

 trees, and prevent the sides of the pit from giving the same check 

 to these roots which the sides of a pot or tub do to the plant 

 contained in it. 



4. The earth being entirely taken out of the pits, ought to be 

 mixed with from a quarter to a half its quantity of good loamy 

 rich soil, and then the whole returned to the pit; and, wherever 

 more than one fourth part of new soil is added to that taken out 

 of the pits, a corresponding quantity of the worst of the soil dug 

 out of them ought to be removed, in order that, when the 

 mixture is thrown into each pit, and heaped up on it, it may 

 contain exactly one fourth part more soil, and no more, than 

 was taken out of it. By these means, the pits, when filled up. 



