Retrospective Criticism. 367 



just as well as he can. In short, I do not think the skill necessary to raise 

 a pine-apple, according to the mode of culture I recommend, is as great as 

 that requisite to raise a forced crop of potatoes." {Hort. Trans., vol. iv. 

 p. 77. Read March 7. 1820.) 



Gardeners, as Nicol observes, and as every gardener and nurseryman 

 knows to be true, being valued by the wealthy in proportion to their suc- 

 cess in the cultivation of the pine-apple, what gentleman, reading the above 

 passage by a horticulturist so celebrated as Mr. Knight, would not think 

 either of changing his gardener, or of lowering his wages ? To confirm 

 such a gentleman in his intentions, or rather, perhaps, to set him at work 

 in reforming the practice of his gardener, the following passage by Mr. 

 Knight occurs in the same volume of the Transactions: — 



" A very great number of gardeners have, within the last twelve months, 

 visited my garden. Some of these were at once convinced of the advan- 

 tages of the mode of [pine-apple] culture which they saw ; others have paid 

 a second or third visit, but everyone has ultimately declared himself a 

 zealous convert." {Ibid., p. 545. Read Nov. 26. 1821.) 



We should be very much obliged to any one of this " very great number 

 of gardeners," all " zealous converts," if he would send us some account of 

 what he saw either then, or during subsequent visits. Why will not our 

 correspondent, Mr. Mearns of Shobden Court, not a very great way from 

 Downton, and mentioned in the Horticultural Transactions, by Mr. Knight, 

 as having seen his pines, send us his opinion ? The truth we suspect to be, 

 gardeners and nurserymen have, like ourselves, so great a personal respect 

 for Mr. Knight, from his obvious goodness, and that peculiar sort of win- 

 ning simplicity and ingenuity which pervades his character, that they will 

 not incur the risk of hurting his feelings. Much and deeply do we regret 

 that our duty as editor has compelled us to run this risk. — Cond. 



yd) The review in question comprising notices of seven articles from 

 Part II. Vol. VII. of Hort. Trans, was wholly by Mr, Main, with the ex- 

 ception of the last sentence of the second article. We do not mention 

 this to excuse ourselves, being unquestionably responsible for every opinion 

 expressed in reviews, to which no signature or mark is attached ; but to 

 admit of any friends of Mr. Knight calling on Mr. Main and ascertaining 

 the truth of what we now assert, that the omission was entirely inadvertent. 

 We regret it extremely on every account, and to atone for it as far as we 

 can, shall here print the article entire, and, that it may not occupy too much 

 room, in a small type, 



" I submit an account of a small addition which I have made to the machinery of a common 

 hotbed ; from the use of which, I believe, that every gardener who has occasion to raise cucum- 

 bers and other plants in winter, or very early in the spring, will be able to derive very considerable 

 advantages. At these periods of the year, it is not easy to give the plants a sufficiently high tem- 

 perature, with proper change of air, however well the bed may have been constructed, and with 

 whatever care the material which composes it may have been prepared; and the sudden changes 

 of temperature, which often occur in the climate of England, will frequently subject the roots of 

 the plants to be injured by excess of heat, and the mould, when lying upon horsedung, to be what 

 is called by the gardener 6i«raerf,- that is, I believe, so much impregnated with ammonia, that 

 the roots of the plants cannot retain life in it. Another defect of the common hotbed is, that 

 whilst its interior part is excessively hot, so little heat ascends through the mould, that a covering 

 of glass alone does not afford sufficient protection to any tender plant, in very cold weather, 

 during the night. 



" By means of the machinery, which I shall proceed to describe and to recommend, abundant 

 air may be given at all times, and so high a temperature preserved, that, with a hotbed of a very 

 moderate degree of strength, the most tender plant will be perfectly protected without any other 

 covering than that of an ordinary glass light during the severest frost of our climate, provided 

 the spaces, where the panes of glass overlap each other, be perfectly closed. 



" The annexed design will give a sufficiently accurate rppresentation of the apparatus which I 

 have above recommended : — 



a, b, c, d, is a hotbed, resting upon an inclined plane of earth, e, the frame. /, g, a pipe, made 

 of a slender oak pole ; and/;, 2, k, smaller pipes fixed into the larger one, through which the air, 

 which enters the latter at /, ascends into the;.hotbed. The tube of the large pipe is one inch and 

 a half, and that of the smaller three quarters of an inch diameter. The smaller tubes have near 

 their upper ends two horizontal apertures, through which the heated air passes laterally into the 

 frame. I consider three of the large pipes to be fully sufficient to give heated air to a bed twenty 

 feet long ; the heated air entering at all times very rapidly, and consequently always keeping all 

 within the frame in motion. The larger pipes might, 1 conceive, be with advantage made of 

 cast-iron. 



