These circumstances have lately induced some amateurs, and also some practical gardeners, to devise means of simplifying the culture of the Pine Apple, and lessening the expenses attending it. The principal amateurs are T. A. Knight, Esq. the President of the Horticultural Society, and Peter Marsland, Esq. of Woodbank, near Stockport; the principal practical gardeners are Mr. Gunter, of Earlscourt, Mr. Hay, a Horticultural architect in Edinburgh, and some others, who have made less extensive trials. SECT. I. _Of the improvements in the culture of the Pine Apple, proposed by T. A. Knight, Esq. F.R.S. P.H.S., of Downton-Castle, Herefordshire._ Mr. Knight’s improvements consist chiefly in the disuse of bottom heat, and in the application of a much higher temperature during sunshine at all seasons, but especially in the summer season, and a much lower temperature during winter, and during the night, at all times, than is generally adopted by gardeners. Mr. Knight had no experience in the culture of the Pine Apple till the year 1819. In that year, he informs us (in a paper published in the third volume of the Horticultural Transactions) that he tried the effect of a very high temperature during the day, in bright weather, and of comparatively low temperature during the night, and in cloudy weather. A fire of sufficient power only to preserve the house in a temperature of about 70° during summer, was employed; but no air was given, nor its escape facilitated, till the thermometer, perfectly shaded, indicated a temperature of 95°, and then only two of the upper lights, one at each end, were let down about four inches. The heat of the house was, consequently, sometimes raised to 110°, during the middle of bright days, and it generally varied in such days from 90° to 105°, declining during the evening to about 80°, and to 70° in the night. Late in the evening of every bright and hot day, the plants were copiously sprinkled with water, nearly of the temperature of the external air. The melon, water-melon, Guernsey lily, fig-tree, nectarine, orange and lemon, mango, Avocado-pear, Mammee-tree, and several other plants, part of them natives of temperate climates, grew in this hot-house so managed “through the whole summer, without any one of them being etiolated, or any way injured, by the very high temperature to which they were occasionally subjected; and from these and other facts,” Mr. Knight continues, “which have come within my observation, I think myself justified in inferring, that in almost all cases in which the object of the cultivator is to promote the rapid and vigorous growth of his plants, very high temperature, provided it be accompanied by bright sunshine, may be employed with great advantage; but it is necessary that the glass of his house should be of good quality, and that his plants be placed near it, and be abundantly supplied with sand and water.” In the above case liquid-manure was employed.