mth bevelled hollcm) Walls. " " 229 



might easily be admitted by direct communications through 

 the soil to the vault, made by a few bricks, a chimney-pot, or 

 a whelmed flower-pot. Ventilators may -be formed in the 

 doors in the ends for supplying manure, in case of too great a 

 heat in the vault ; and plugs, or wooden blocks, with rings 

 for convenient handling, may be placed in one or two places 

 in the back and front walls, to admit, through the hot vacuity, 

 fresh air to the plants in very severe weather. As the outer 

 surface of the end walls will be fully exposed to the weather, 

 they should not communicate with the side walls, but should 

 form distinct hollow walls of themselves ; and in order to pre- 

 vent the escape of heat from the outer surface of the back and 

 front walls, a space of a foot or more between them and the 

 soil in which they are sunk should be filled up with loose 

 stones or brick-bats (?z). 



A very convenient length for such pits will be 1 6 ft., in 

 which case there may be a door at each end, with a ventilator 

 in each door ; but, if they are made longer, there must be a 

 door in the centre of tbe back wall of the one pit, and of the 

 front wall of the other, for the more easily admitting and taking 

 out of the dung. For growing the earliest crop of cucumbers 

 or melons, however, a double range of 1 6 ft. is surely sufficient 

 for any family whatever. 



This principle of building hollow walls with bevelled sides, 

 I should think, might be adopted with advantage in the case 

 of high garden walls, laying the bricks flat in the usual man- 

 ner instead of on edge, and taking care that the coping shall 

 project as much as if the walls were as broad at top as at 

 bottom. Whatever might be the height of such walls, there 

 never could be any occasion for piers, which are always incon- 

 venient and unsightly objects in a garden. Perhaps the same 

 principle might be advantageously applied to cottage-building, 

 and to the erection of various descriptions of agricultural 

 buildings. The only difficulty in constructing such walls will 

 be that of the cross bond, which cannot conveniently be car- 

 ried up in the usual manner, but must be limited to certain dis- 

 tances, say every third brick, at which distances brick-on-edge 

 partitions (j^. 68. k k) should be carried up from the founda- 

 tion to where the wall is narrowed to a brick's length. In 

 walls not exceeding 1 2 ft. high, I should think the brick par- 

 titions might be dispensed with, because the two sides (/ 1) 

 will be equivalent to two 9-inch walls, held together by their 

 inclined position, and by the superincumbent weight of the 

 boarded 9-inch wall (m). Various descriptions of coping {n n) 

 might easily be contrived for such walls. I remain, Sir, &c. 



Alfred Kendall. 

 Wanlip Hall, Leicestershire, July 3. 1827. 



o 3 



