Dear Sir - I take it lor granted that there are a good many among your readers, who, like myself, love gardens, and are too poor to have all the luxuries that belong to them. Among these luxuries I count green-houses and hot-houses. Now, as I dont spend fifty dollars a year on my garden, besides my own labor, it is not to be supposed that I have any such "Crystal palaces." Yet I contrive by the aid of cheap pits or frames, sunk in a dry warm part of my garden - under the sooth side of aboard fence, to keep through the winter all the half-hardy plants, such as tea-roses, carnations, petunias, heliotropes, and most of the hardrwooded green-house plants that adorn the garden, and keep it gay in summer. Chinese Azaleas do even better in these pets, than they do in green-houses. To make such frames, it is only needful to choose a piece of ground that is well drained, to have a few good hot-bed sashes, to make a frame or bottomless box, out of some rough boards, as wide as the sashes are long, and as long as the sum total of feet that your sashes will coyer if laid side by side. Sink the frame in the ground to its level, within two inches at the front, and three inches at the back, so as to make the needful slope to carry off the rain.

Dig out the soil for two feet deep* Spread a couple of inches of small stones, or coal ashes at the bottom, and set the pots open this. Give as much light and air as you can until severe frosty weather sets in. In. downright winter weather keep the frames shut pretty close, covering the glass at night with several thicknesses of matting or old canvas bagging - and in very hard frost, with a few bundles of straw in addition. Water only when the pots appear somewhat dry - but then water freely - especially if the weather is such that you can keep the. frame open for an hour or more.

In this way, almost all the popular and showy greon-house plants may, as I have said, be wintered in excellent condition, at very trifling expenses, no artificial heat, whatever, being required. Wishing, however, last winter, to do something new, and have a few really tender exotics in a pit, I hit upon a cheap and simple sort of warming apparatus, which succeeded quite to my satisfaction, and I must therefore describe it to you.

My heating apparatus was a large flat, tin lamp, with a common candle wick - the lamp large enough to hold a pint of alcohol - for this was to be my fuel. Over this lamp, at the distance of an inch and a half, was suspended or fixed my boiler - about six by eight inches, also tin. Out of the side of this boiler, about one-third of the way down, started a tin pipe, one inch in diameter, tightly soldered to the boiler, and also at every joint. This pipe ran quite round the frame, (suspended a little way from the board by a wooden bracket,) and finally entered the boiler again near the bottom, on the side opposite where it went out. The boiler itself was soldered quite tight, and the whole pipe was quite tight - with the exception of one place; this was the first elbow after it left the boiler - one-third of the way round. Here it had an upright joint soldered on, reaching up to near the glass - say two inches higher than the level of the water in the boiler: This upright joint was open at the top, and into this opening I daily poured the water to fill the boiler, pipe and all - for you see it was in fact all one boiler.

I had then, as your readers well and warm the frame admirably, without any danger of over-heating, and in ordinary nights, (the frame being well covered,) I needed no fire. Soon after the lamp was lighted, the warm water began to rise in the boiler, and to flow off through the topmost pipe, and as it became cooled it returned to the bottom of the boiler, by the lower part of the same pipe - and although, of course, the water never became hot, it was quite warm enough, not only to raise the temperature of the frame, but to keep it raised - as the water once heated remained so a long time after the lamp went out.

I ought to add, that at the end of the frame, where the lamp was fixed, I had a little box, or double door, by which I could light and feed the lamp without letting cold air into the frame.

I have sent you this account of my simple, experiments,, which will appear insignificant enough to many of your readers, thinking that some few of those to whom "necessity is the mother of invention," might find a useful hint for their own practice.

Yours truly, An Original Subscriber.

New-York, September, 1851.