370 Retrospective Criticism, 



of a ventilator in any part of the wall, and an ascending tube fixed thereto 

 on the outside, which will keep a continual circulation of air without open- 

 ing of doors or lights. 



Another improvement I have also made for heating of pine pits, frames, 

 &c., without the aid of tan or hot dung, by means of a trough about 1 ft. 

 6 in. wide, more or less, as occasion may require, which may be made with 

 bricks set in cement, with stone, or with any other material that will hold 

 water. This trough is to lie under the pit, and a pipe is to pass through 

 it to heat the water; and a common wood hurdle is to be placed over, 

 about one foot off, with straw or leaves on the top, so that the heat and 

 steam may pass through to the mould. I am, Sir, yours, &c. — Edward 

 Weeks. Horticultural Manufactory, King^s Road, Chelsea, Nov. 11. 1832. 



Thoughts and Facts on the Effects and Principles of Pruning, by Mr. 

 Howden. — Sir, Mr. Billington and you have " spun a mortal long yarn," 

 about " ignorance in arboriculture, with hints for its removal," all seem- 

 ingly directed against poor Howden. (p. 50 — 39.) Nine full pages ! oh, my 

 patience ! and 1 would not give a fraction of a farthing for all his dry, 

 musty, worthless palaver. Friend Taylor is wrong in supposing (p. 49.) 

 that I am a disciple of the old school : I trust I have advanced at least 

 one step higher than that of the new school. I properly appreciate the 

 value of leaves, twigs, and branches ; I should be sorry to deprive a tree 

 of one of its leaves in summer, or to see them devoured by the locusts or 

 caterpillars ; I should be sorry to deprive the peacock of one feather of 

 his gaudy train ; but I should be more sorry to be such a ninny as to call 

 the eyes of Argus the mouths, or heads, of Medusa. If the poor bird had 

 not another mouth at the other extremity it would never get fat. The 

 whole of Mr. Billington's nine pages, with quotations from better men 

 than himself, only go to prove that to tear off a young leaf draws part of 

 the bark with it, while a ripe leaf drops off at a joint ! Pray, Sir, will not 

 tearing out a young feather from a fowl tear the skin, and even draw 

 blood ":' while, if left to nature, they will all drop off at a joint, the same as 

 leaves : but when do the branches of a tree drop off at a joint ? Answer. 

 Never; and so the skilful pruner makes an artificial joint with his knife, 

 hook, or chisel. Question. When does a branch rot and drop off from a 

 tree, leaving part of its decayed stem in the stem of its mother r" Answer. 

 As soon as the higher branches meet, so as to exclude the sun and air; for, 

 as few trees will live under the drip of others, so few branches will live 

 under the drip of their younger brethren. Question. Then, what is the 

 use of pruning, if trees, planted at proper distances, will prune themselves 

 naturally ? Answer. Very few deciduous trees will prune themselves, 

 unless firs or evergreens are planted among them, by which thej' are 

 both sheltered and drawn up straight. Then, to take away the firs, &c., at 

 once, would expose them too suddenly to summer's heat and winter's 

 cold, and they would become hidebound and stunted ; but, by pruning the 

 firs, the sun and air are let in among the trees, and the ground is warmed, 

 and vegetation encouraged. Then, a plantation wholly of firs will grow 

 better if planted 4- ft. apart than if planted 4 yds. apart, if so be that by 

 pruning you admit the sun and air to warm the soil, and so invigorate the 

 trees, that you do not need to fall any tree before it is fit for a 9 ft. rail ; 

 whereas, without pruning or thinning, it would be a mass of rubbish, like 

 an unhoed crop of turnips, all rotting on the land ; but 4 yds. being a 

 proper distance for a timber tree of 100 cubic feet (as proved on the 

 estates of the Duke of Athol), then the pruner has 2722 rails on his acre; 

 of which he sells 2420 rails or poles, leaving 300 timber trees on his acre, 

 which, in 72 years, it appears, are worth perhaps eight or ten pounds sterling 

 each tree. Now, the pruning costs no more than 10.?. per acre; and 2420 



