498 



Notes on Arhoretums : — 



mmm^ 



readers wlio are willing to aid us in rendering our Arboretum 

 Britannicum as perfect a work as possible. 



At Syon House, we were struck with the vigorous appearance 

 of the lime trees in the avenue, owing to the soil being kept 

 moist by the adjoining water. The lime trees not so situated 

 are every where, in this very dry season, losing their leaves ; and 

 therefore it ought to be the object of a perfect system of artificial 

 culture and management, to supply water, as well as cultivation 

 by stirring the soil, &c., and giving manure. We have thought 

 of a variety of modes of supplying water to the trees in the 

 arboretum in the Horticultural Society's Garden, during the 

 months of June, July, and August, in every year ; and we are 

 convinced that the cheapest and most effectual method would be, 

 ^^ to form a series of covered drains, 



about 6 in. deep, and 2i in. wide, 

 formed of bricks ; as in^/g-. 82. The 

 appearance of the top of the drain 

 would be as va^gs. 83 or 84.* The 

 upper surface of the bricks, being 

 exposed to the air and weather, would 

 soon assume a dingy colour, so as to present no eyesore as con- 

 trasted with the green turf, and being as perfectly even and 

 smooth as the ground on each side, would offer no 

 obstruction to walking, rolling, or mowing. The 

 drain would be formed without mortar, in order to 

 let the water escape at the bottom and sides, and 

 to admit of taking off the top bricks to clear out 

 any roots of the grasses or trees, or other obstruc- 

 tions which might be formed in it. The chief diffi- 

 culty in such a system of watering would be, to lay 

 out the drains in such a manner as that every part 

 of the ground should be equally watered. This 

 can only be done by adopting the modes employed 

 in surface irrigation on hill sides; viz. beginning 

 on the highest ground, and winding about, always 

 under a certain degree of steepness, till the lowest 

 ground was reached. The distance between the 

 drains would depend on the porosity or compact- 

 ness of the soil. The supply of water would, of 

 course, always be given at the highest point. In 

 comparatively level ground, such as that of the 



* We shall here make a remark on Jigs. 83. and 84., for the benefit of young 

 gardeners. Both these figures represent common bricks laid on their flat sides, 

 alternately crosswise, and lengthwise, so as to form a chain, which we may 

 imagine sunk into a lawn, so that the upper sides of the bricks may be exactly 

 level with the surface of the lawn. Fig. 83. is drawn with the aid of a square, 

 and a drawing pen ; 3Xid.fig. 84. with a common pen, and by the eye, without 

 the aid of rule, compass, or square. Now, the question is, which of these 



