three inches in the centre, thus leaving a fall for the water to run as the steam condenses. These boxes are particularly convenient for the workmen, as they turn out their work much cleaner than by the usual process, not having to attend to their charcoal fires.

Another advantage is, that injury to the health of those employed is thus prevented, as every person must be convinced of the unhealthy state of rooms where charcoal is burning in open pots, without flues, from which both noxious fumes and particles of fine dust are continually escaping. Of these boxes I have introduced three only in the drawing, thinking them sufficient for expla nation; but I should be very happy to attend the Society at any time to give any farther explanation that may bė required.

:

EE, I call the drums, the first I had made being of that form it is a double cylinder of metal, with spaces of half an inch for the steam to pass through; by this means the cylinder becomes heated, and the air passing through the centre, also becomes heated to any degree required for drying the goods.' G is a vessel in which the steam from the drum is condensed. H is a cistern, supplied with water by means of the pipe on the right hand, for the purpose of affording water, by the pipe I, to the boiler; the water collected in the condenser is also discharged into the same pipe, and a stop-cock from which furnishes water to the open cistern J.

Another use to which the stove is put, is that of throwing hot dry air into the drying-room, and extracting the damp air. The apparatus which performs this latter office, acts on the principle of the reversed syphon. a, is an open aperture in the side of the stove, Fig. 3, which admits the external air into a cast-iron box b, which surrounds the upper part of the fire: here the air being

heated,

heated, passes into the drying-room through the tube c. When cooled and saturated with moisture from the wet paper in the rack K, it falls through the tube d into the boxes ee, which surround the lower part of the fire, and being thus again heated, rises up the tube f into the drying-room.

Fig. 4 is a plan of the stove, for the purpose of showing the boxes of cast-iron surrounding the fire-place.

Figs. 1 and 2 are a section and plan of the drum E. Fig. 5 represents a section of the heating plate D, and of the steam-pipe C, to show the manner in which they are connected.

Fig. 6 is a section of the steam-box at right angles to the former section, showing the form of the box.

Figs. 7 and 8 are a view and section of the method by which two pieces of steam-pipe are joined together; c is a washer interposed between the two shoulders, in order to prevent the escape of steam, and on the outside of the two shoulders are two flanches, through which the screws dd, Fig. 7, pass, and thus secure the joint.

Figs. 9 and 10 show the method of joining two pipes with an interposed stop-cock f, Fig. 9.

Fig. 11 shows the flanche with the hole C, through which the steam-pipe passes, and the holes ee for the screws or bolts d d.

Figs. 12, 13, and 14, exhibit a view and section of a valve fixed at certain distances, in the steam-pipe, for the purpose of admitting the external air, when the condensation is greater than the supply.

Deduction

Deduction and Application of the Laws of Nature, ordained for the Support and Government of Vegetables.

From the SCIENCE of HORTICULTURE, &c.

By JOSEPH HAYWARD, Gent.

FOR whatever purpose we suppose vegetables to be

created, it is clearly the order of Nature, that all kinds advance by progressive degrees in their growth to attain the fructiferous state; and as it is in the perfect accomplishment of this that fruit-trees become valuable to mankind, and the seed or fruit the chief object for which they are cultivated, the attention of an artist, in training and pruning, must be principally directed to the means required to assist Nature in the attainment of this her purpose.

To arrange therefore a system of raising, training, and pruning fruit-trees, in a scientific manner, it will be necessary, first, to lay down and explain those laws or principles of Nature which are ordained for their support and government, and more particularly of those plants or trees that form the peculiar subject of the present work; and with this view I shall reduce them to the eight following theorems.

First. The roots of plants are gradually extended and impelled forward into the earth, and annually collect, absorb, and dispense, an increased quantity of food, so long as they grow unobstructed.

Second. Water, holding in solution certain animal and vegetable matter, constitutes the food of plants, and a current, change, or circulation of water in the soil, is necessary to sustain the life and preserve the health of plants.

VOL. XXXV.-SECOND SERIES.

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Third.