boilers and tubes burnt out since the hot-water system commenced, that we deem it our duty to state, thus freely, our opinion. It is true that east-iron tubes, such as those of Mr Weekes, or the wrought-iron ones of Mr. Perkins, may be renewed at very little expense; and also that, if distilled water only were used, the deposit would be much longer in taking place. In particular situations, therefore, the tube system may unquestionably be the best.

Cond.

ART. VIII. A short Notice of Mr. Busby's Method of circulating Water, hot or cold, by the Aid of Machinery. By the CONDUCTOR. THIS method is described at length in the Repertory of Patent Inventions for September, vol. iv. new series, p. 137. As it is not particularly adapted for hot-houses, we shall not go much into details; but simply state that the circulation is effected by an apparatus which may be compared to the wheel of a winnowing machine, and which is fixed on a perpendicular axis within the boiler (which must be circular), with its axis as nearly as possible over the end of a pipe which reaches from the circumference to the centre of the boiler. There is another pipe, which reaches no farther than the circumference. These two pipes may descend or be conducted to any distance, being united at their farther extremity so as to form only one pipe. The whole being then filled with water, the fan or circulator is made to revolve, by the action of the smoke and hot air of the chimney-flue, upon the fans of a common smokejack; and the result is, a rotatory motion communicated to the fluid in the boiler, the centrifugal force of which will so act against the fluid in the pipe terminating in the circumference, as to force the water down it, while it draws it out of the other. It is evident that, by this apparatus, either hot or cold water may be circulated with equal ease; the circulation depending entirely upon the centrifugal force, and the orifice of one pipe being in the centre, and the other in the circumference, of the boiler. The result is certainly such as would not easily have been anticipated. "To prove the efficacy of his invention, Mr. Busby has had an apparatus, on his principle, fixed on the premises of Mr. Eckstein, ironmonger, in Holborn; and, on the 9th of August, a numerous meeting of engineers and gentlemen of science took place, to witness its performance. The furnace is situated in a workshop on the second floor; and the heated water, urged by the circulator, passes through inch pipes to a receptacle in the open shop on the groundfloor, having descended 21 ft. below the furnace. The experiment succeeded completely, and gave universal satisfaction.

"Mr. Busby considers his invention of general application; for, besides forcing the hot water downwards, an object never before accomplished, he causes so rapid a circulation in the ascending and level pipes, as to be enabled to employ tubes of much smaller bore than are now used. He can, besides, make water ascend and descend again about doors and windows, pass beneath floors; and, in short, he can carry his pipes in any direction whatever, without sensibly impeding the circulation of the hot fluid." — C. A. B. (Rep. of Arts, vol. xiv. p. 143.)

We were present on the occasion of the trial alluded to, and were much gratified. The following figure (fig. 2.), taken from the Repertory of Arts, will give a general idea of the apparatus, as exhibited at Mr. Eckstein's:

2

g

a, A common fire-grate, fixed in a garret over the back shop. b, The boiler, with the circulator within it. c, Smoke-jack wheel, fixed on the same axis with the circulator. d, Descending hot-water pipe. e, Vase in Mr. Eckstein's shop, 21 ft. below the garret, which is kept full of circulating hot water by the descending hot-water pipe. ff, Ascending pipe, by which the water is returned to the boiler, to be reheated. g, The garret floor. h, The shop floor.

In heating dwelling-houses, and in cooling or heating liquors in manufactories, it is evident that this most ingenious invention may be turned to good account.

ART. IX. A Mode of obtaining Uniformity of Temperature, and various Modes of Engrafting. By CHARLES M. W

Sir,

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I AM not aware that the following method of obtaining uniformity of temperature has been tried. I placed a small pot with a cutting from a delicate fairy rose in a larger pot (fig. 3. a), containing charcoal, with a double glass over it (b), so as to leave a stratum of air between the glasses. Although it was tried late in the season, and placed in a green-house without any artificial heat, yet it succeeded. The object in view was, to surround the pot by a non

a

conductor of heat, such as charcoal.

The stratum of air

between the glasses produced a similar effect.

1

,,

The plan of inarching with a cutting, mentioned in Vol. III. p. 29., suggested to me the idea of laying a cutting, and inserting the end in a bottle of water (fig. 4. c).

J

4

I have lately tried a cutting of Lonicera flexuosa, and I feel very sanguine of success. I have lately met with an old book written by the celebrated John Evelyn, which he calls Kalendarium Hortense. I was much surprised to find in it many remarks and advices which have from time to time been promulgated as novelties. It would appear that John Evelyn was the inventor of the method of warming green-houses with heated air. In the above book are drawings and descriptions fully explaining the way in which it may be effected. If I mistake not, patents were taken out some years ago for heating houses on that plan. In his remarks, under the month of July, he says: "Now with lime, brine, potashes (which is the very best of all, because, being cast on fine turf, it destroys the worms and improves the grass, which most other applications mortify) and water, or a decoction of tobacco refuse, water your gravel walks, &c., to destroy both worms and weeds, of which it will cure them for some years." Soot is also recommended. He also says, "In wall-fruit borders, which should be 4 or 5 ft. wide, plant neither herb or flower." He mentions "that sick trees, as oranges, &c., are many times recovered by a milk diet; that is, diluting it with a portion of water discreetly administered, as you find amendment." I do not remember seeing this last recommendation in any late writer. It may, therefore, pass for a novelty. As to removing trees, of which so much is written in our time, he says, "That you may transplant not only any fruit trees, but remove almost any of the foresters, even in the midst of summer, if, taking the trees with some mould about the roots, you immediately plunge them into earth made into a pap like mortar, keeping it fresh and under shade, and not suffering the ground quite to dry up and harden till rain comes down." This very much resembles some of the modern plans. As to straw mats lately, so strongly recommended, he says, in the month of November, "Cover also your most delicate stone fruit and murals, screening them with straw hurdles, as long as the east and northern winds continue, even to the end of March, to be sure of the fruit. Stand, therefore, not so much upon the beauty, as for its preservation and production.'

I think the following advice which he gives, though not entirely new, is good. For plants not placed in the conservatory, and not hardy, he recommends, "that the pots should be placed two or three inches lower than the surface of a bed': with southern exposure, having clothed them first with sweet and dry moss; but upon all warm and benign emissions of the sun, and sweet showers, give them air," &c.

I will not draw farther on the stores of the worthy John Evelyn; as, before I conclude, I wish to call the attention of your readers to a new plan of grafting, called by Monsieur Vergnaud Romagny*, écusson greffe, or shield-grafting. It may be universally practised on all the ligneous tribe, whether trees or shrubs, either on the old or on the new wood; but the latter is to preferred. The stock should be vigorous, and the sap by preference ascending: it need not, however, be very abundant; nevertheless this disposition is more advantageous than hurtful. The stock, whether young or old, should be clean cut horizontally, from half an inch to one inch (according to the species) above a bud which is somewhat developed, and the extremity of which should be pinched off; or a small shoot on which one or two eyes may be left. The bark is to be divided by a vertical cut, from one to nearly two inches in length, according to the size and strength of the stock, the distance from the bud or shoot near the horizontal cut, and also according to the species, as from a to c, fig. 5. Either the right or the left side of the bark, 1979709291 guided by the neighbourhood and posi

970891 ud

tion of the bud or shoot near the vertical' cut, is to be raised with the handle of the budding-knife, taking great care not to touch or injure the opposite side. In fig. 5., the left side (a) is raised opposite the bud (d), and the right side (b) 'reHi Jembe mains untouched. The graft should be -ammi voyons taken from a healthy and vigorous subTom bu qe ject. It is a shoot of young wood cut to sistua for a certain length, according to the position of the eyes (gemmæ) of the species. If both the graft and the stock are in perfect health and full of sap, three or even four eyes may be left. Fig. 6. has three at . The shoot is to be cut across, a little above the first superior eye; and, below, it must be cut sloping (en sifflet), as from h to k. At the notch h, half the thickness of the wood is to be cut away. The side g will be oblique, and the side ƒ quite straight. Fig. 7.

* From the Recueil Industriel, par M. de Moleon.

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7

is a front view. It will be observed that at the notch n half the wood is scooped away, and that the graft has only a thin portion of wood two thirds of its length, and that at o only the peel or bark remains, also that the sides ƒ and g (fig. 6.) have only bark or peel on their edges, The graft thus prepared will slide into the opening prepared in the bark of the stock (fig. 5.), so that the edge of the bark of the graft joins the edge of the bark (bc) in the stock. The notch (n) resting on the horizontal cut of the stock, and the bark of the stock (a c, fig. 5.) almost covering the graft. Held in this position by the thumb and finger of the left hand, it should be tied tight. with bass, covering the whole of the opening. Afterwards apply grafting-wax,* to prevent the contact of the air with the recent wounds of the stock and graft. The graft may now be left to itself. The only care

8

9

which it requires is, that the stock should be freed, from time to time, of any buds which might absorb part of the sap; and support given, if the graft grow very rapidly. Figs. 8. and 9. show an advantageous modification of shield-grafting, which M. Vergnaud Romagny believes has not been practised. It always succeeded, and is preferable to the other mode, when operating on the young wood, or with the more delicate species. This modification consists in preserving an eye on the lower part of the graft, as at 7 m, fig. 8., and

m

*The following receipt for grafting-wax will be found good, the heat of the body or the mouth rendering it sufficiently soft for use:- Take common sealing-wax, any colour, except green, one part; mutton fat, one part; white wax, one part; honey, one eighth of a part. The wax and the fat to be first melted; then add gradually the sealing-wax in small pieces; keep it constantly stirred; and, lastly, the honey, just before taking it off the fire. It should be poured hot into paper or tin moulds, and kept slightly agitated, till it begins to congeal.