The greatest difficulty experienced by the residents in large towns who desire to cultivate plants on their balconies, or, as some say, who would wish to have Hanging Gardens, is to find some satisfactory manner of heating them. Common hot-water apparatus is much too powerful for such small places, to say nothing of cost, or the great difficulty of applying it; and when gas, the obvious substitute, has been employed the atmosphere has been rendered unfit for the respiration of plants. This has been so notoriously the case, notwithstanding many ingenious contrivances, some of which may be found described in former volumes of the Grardeners' Chronicle, that all idea of applying gas to greenhouses has for some time been abandoned. It appears however from the following account, for which we have to thank our very intelligent correspondent at Trentham. that the difficulty has been wholly overcome. This announcement is of such universal interest that we feel it a public duty to give the invention all the publicity in our power.

"Having occasion," he writes, "to pass through Edinburgh a short time since, I availed myself of the opportunity thus afforded of visiting Dalkeith, and among other things which particularly interested me was a method of heating living rooms and greenhouses by means of gas. The apparatus consisted of what may be called a heater or stove containing water, through which the air heated by a gas jet underneath the stove is carried by a pipe, coiling round and round in the water until it arrives at the top, from whence it is conveyed into the chimney. The warmth may be perceived the moment the gas is lighted, and can easily be regulated by means of a tap. There is not the slightest smell of gas perceptible, and an entire absence of dust or sulphurous smell as from coals. The cost of heating a large living room apparently about sixteen feet square and proportionately lofty, is I am informed only about threepence per day. The advantages of this plan in an economical point of view are undoubtedly great, and with regard to cleanliness I will merely remark that the lady of the house informed me it had been in use more than a year, and that she should feel very sorry were she obliged again to have recourse to coal fires, as there is no dust or dirt of any description from the gas apparatus, and when a room is not required the gas can be turned off in a moment without any fear of accident.

"The inventor and patentee, Mr. Thompson, of the Dalkeith Gardens, in whose house the trial was first made and with perfect success, explained the manner of fitting up the apparatus, and from bis remarks and my own observations I have not the slightest doubt either of the efficiency of its heating powers or its cleanliness. The temperature of a greenhouse heated in this manner was 75° when I was shown into it, and the gas had then been turned off about half an hour. The stove stood on one side of the entrance, and from it a flow and return pipe two inches in diameter was carried round the house. It is however needless to attempt a further explanation of a system at once so simple and so effectual as to cause surprise that the same kind of thing has not been put in operation before.

"I understand that Messrs. Thomson and Sons, plumbers, of Dalkeith, are preparing to manufacture this apparatus in quantities, and I feel sure that when it has had time to become more generally known it cannot fail to be properly appreciated. Dwelling houses, small greenhouses, offices, warehouses, etc, particularly in towns or their vicinity, where gas can easily be obtained, may thus be thoroughly warmed at a very cheap rate. Portable greenhouses also, in one of which I saw this method of heating in operation, may now be manufactured either for exportation or otherwise, with the gas stove and pipes complete.

"In every other plan of this description which has come under my notice there have always been complaints either of the gas escaping, or of the air of the place being burned or other ways rendered impure or deleterious; but in this instance, owing to the small quantity of gas used, the low situation of the burners (on what would be the hearth of a common fire), and the effectual but simple manner of getting rid of the heated and impure air, these objections are entirely obviated".

Heating By Gas 130064

Fig. 1.

Heating By Gas 130065

Fig. 2.

That some such contrivance as this had been used near Edinburgh we had previously heard, but in the face of so many former failures, we declined making any statement on the subject until satisfactory horticultural evidence could be obtained. This now appears to be sufficient.

Upon making inquiry concerning the apparatus in question, we find that it is the invention of Mr. Thomson, gardener to his Grace the Duke of Buc-cleuch, Dalkeith Park, who is also the inventor of "Thomson's Retort Boilers," now coming into general use for heating forcing houses, Ac. The apparatus is described as consisting of a zinc or copper column, containing from five to twenty gallons of water, having an inverted copper cone as a bottom, on which the jet or jets of gas play, and from which the heat ascends and exhausts itself in the water in a series of helical tubes, collecting into a larger tube at the top; by which means all unoonsumed gas and noxious products of combustion are canned, either into a chimney, or through an aperture in the wall to the external air. Thus a large body of hot water is obtained, from which a perfectly pure and wholesome heat is radiated.

Another important point is that its management is as simple as lighting a common gas jet, requiring no regulation beyond turning down the gas when the temperature is rising too high.

The accompanying figures will further explain the nature of the contrivance: -

Fig. 1. represents the external appearance of one of the handsomer patterns; Fig. 2 a section common to all, the only differences among them consisting in decoration and size. The letters in the latter explain details, viz. - A, exit of hot air from gas burner to vent; B, entrance for hot air from gas burner to spiral tubes; C, entrance for cold air to expel heated air from chamber; E, hot air chamber; D, opening for the supplying water to boiler F; G, gas burners; H, aperture for emptying boiler; L, guage for water level.

The price of the apparatus will necessarily vary with circumstances. A stove like Fig. 1 holding six gallons of water is 5l. 5s.; this we suppose is exclusive of fixing, etc. But upon such matters inquiry must be addressed to the makers.

The only probable source of failure that occurs to us at present is that the apparatus may be imperfectly constructed, in order to meet the exigencies of the numerous worshippers of low price, under the mistaken idea that they are sacrificing at the shrine of cheapness. - London Gardeners' Chronicle.

Heating By Gas #1

In the present number we give currency to an article, explained by cuts, on heating plant-cabinets, and houses, etc., by gas, with a view of inducing our American mechanics to look into the matter. There are many citizens who would gladly employ such an apparatus, and country gentlemen who manufacture their own gas; when they possess the apparatus all the extra gas wanted is made at a small additional cost.

In contriving such a gas stove, it must be remembered that common lighting gas is the most searching and deadly poison to plants, and it should never be risked to contaminate the air which they should breathe. No air from the house or room to be heated, should be admitted to the inside of the stove for fear of contamination by leakage; the air to sustain combustion should come from a cellar, an adjoining room, or from the outside through an underground drain or pipe, and it should be discharged when used, with the greatest care, that none escapes for the injury of the pores of the plants. The subject is an interesting one, both on account of its convenience and probable economy.