INDEX TO GRAPERY.

the border is vaulted; they may be thoroughly protected from frost, but cannot be warmed to any considerable extent, and are consequently less stimulated than the cane and leaves, and do not contribute as largely as the latter require.

Vines which are to be grown from pots are started from cuttings or better, from eyes which are induced to grow as much as possible the first year, to insure strong plants. When the leaves have all fallen, prune to nine inches in length; keep them through the winter in some dry place well protected from frost. In January or February shift them for the last time into larger pots,not less than a foot in diameter, thoroughly drained, and filled with earth well mixed with rather coarse old turf. Allow as many

shoots to grow as can conveniently be accommodated in the place where the pot is to stand; some cultivators retain four or five branches, others but one or two; perhaps one cane is as much as is really judicious. Stop it about five feet long; as often as it starts afresh, stop it, and pinch off the laterals.

In September the plant will lose its leaves, and should be pruned to about 3 feet long for a 12 inch pot, 4 or 5 feet for a 15 inch pot, every additional inch in the diameter of the pot allowing an additional half-foot of cane, although the ultimate length must be regulated by the space allowed during forcing. If the plant is to be forced early, set the pot over the flues or pipes late in December. The culture of potted vines will be described at another time.

DESCRIPTION OF GRAPERY. - Having explained the practice to be followed in our grapery, I proceed to describe the building itself. Refer to the ground plans and elevations on next leaf, in connection with the description.

A B C is the grapery; A, retarding-house; B, cold grapery; C, forcing-house; D, shed for boilers, etc.; E, boiler; F, cistern.

The back wall of A is 16 feet high, the front 5 feet high, of which 2 is solid, 2 glass, as in the greenhouse; the building is 12 feet wide. B is 20 feet wide, 6 feet high in front, 14 feet in the middle, 9 feet at the back. C is 12 feet wide, 13 feet high behind, 4 feet in front, of which 2 feet is brick, 2 feet glass. The ar

rangement for ventilation through the wall at the side and top is the same as in the greenhouse and the conservatory. The back wall of C is 2 feet thick, 6 inches of the distance being an air chamber. The back walls of A and B are 1 foot thick; all front walls are 1 foot thick; side walls to glass, 1 foot; above glass, posts, and window sashes, 6 inches in the rough, worked down enough to look well without losing strength. E, the boiler, will be described hereafter. F, the cistern, collects the water from the roofs; there is a well in the shed which can force water into the cistern at need.

The heating is done by means of 4 inch iron pipes, which are carried round the inside of the different buildings, just as in the greenhouse, only that the hot water may be carried into either division of the house without warming the rest any more than would be done by one-half the leading and returning pipes through the grapery, as the water is carried either to the forcing or retardinghouse. The heat derived from this amount of pipe is not enough to much affect the cold grapery; it does not do much more than take the chill off the air at those seasons when this part of the house is intended to be dormant.

The smoke is carried in a brick flue shown by dots, into a flue which runs under the walk in the cold grapery, through to the farther end of the forcing-house, and thence up the chimney. In order to allow the pipes free range about the house, without the extra expense of bends, elbows, etc., the sill of the door is raised so as to be reached either from without or within, by two steps, under which the pipes pass quite out of the way.

On all sides of the forcing-house, grapes are planted. The border is at one end and in front, and takes the roots of the vines in those parts of the house; at the back and the inner end vines are planted in the floor of the grapery, which is a regularly prepared border, and is enriched annually with liquid manure. There is a table on the right of the walk, on which vines in pots are placed for forcing; and over the whole course of the pipes is a narrow table, on which strawberries and some early vegetables may be forced. The vines are brought into the house through cylindrical, oblique holes, 6 inches in diameter in the front and side walls, just between the foundation and the first course of bricks. The

hot-water pipes are 1 foot from the vines, along the front and back, 6 inches at the ends. Under the middle table is a mushroom bed. The arrangement of the retarding-house is similar; but the front shelves may be used to start hothouse bulbs, and low growing plants for exhibition in the greenhouse and conservatory.

The cold grapery has vines along the sides and ends, and one row in the middle near the walk; but the immediate front is occupied by an espalier, on which are grown Cherries, Peaches, Apricots, and Nectarines.

It is a very nice matter to heat such a building as this, for it is difficult to calculate how large a boiler, or how many feet of pipes are necessary. A formula is given below by which the necessary calculations can be made.

The amount of heating surface of pipes to be allowed, depends on the number of cubic feet of air which are to be heated per minute, and on the difference between temperatures within and without. Upon the number of feet of pipes depends the size of the boiler; and the efficiency of the boiler is determined by its shape, setting, and the distance between the furnace bars. Messrs. Tredgold and Hood, in England, have made the most reliable calculations on this matter, and their directions are accordingly quoted, as follows:

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"If,” says Mr. Tredgold, "the cubic contents of air to be heated per minute be multiplied by the number of degrees it is to be warmed, and the result be divided by twice the difference between the temperature of the house and that of the surface of the pipes, the result will be the feet of surface of iron pipe required.

"Thus, if 1000 cubic feet per minute are to be warmed, and the extreme case is supposed to be that when the external air is 20°, the house should be warmed (to) 50°; and therefore the air is warmed 30°; and with water (within) the surface (of iron pipes which contain water) will be 190° when the water boils, but only 180° in its average state; therefore,

Mr. Hood gives another formula for ascertaining the number of feet. He says that 11 cubic feet of air must be heated for each

:

square foot of glass in the building. Multiply 125 by the difference between the proposed maximum temperature within and the temperature without, and divide this product by the difference between the temperature of the pipes (average of surface 180°) and the proposed temperature of the room or house; then the quotient thus obtained, when multiplied by the number of cubic feet to be warmed per minute, and this product divided by 222, will give the number of feet in length of 4 inch pipe, which will produce the desired effect. If 3 inch pipe is used, the number of feet of 4 inch pipe must be multiplied by 1.33; if 2 inch pipe is used, by 2.

The number of feet of pipe being thus obtained, the corresponding boiler surface may be ascertained from a table of proportions given by Hood as follows:

“When the difference in temperature between the pipes and the air to be heated is 140° (pipes 200° — air 60°),

and so on; the figures of the 4 inch column being increased onethird to give those of the 3 inch, and doubled for the 2 inch.

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Again, when the difference in temperature is reduced, say to 120° or 100°, a boiler of the same size as above will heat one-sixth and one-third more than when at 140°."

A FORMULA FOR CALCULATING SIZE OF BOILER. - Take the cubical contents of house, and to every 100 feet allow 10 square inches of boiler surface, and 1 square inch of fire grate.

Much depends upon the distance between the pipes at their junction with the boiler; they should not be less than 16 inches from centre to centre of 4 inch pipes.

When the boiler is not more than 18 inches deep, it is best to lead the flow pipes from its top, and insert the return pipes as near the bottom as connection can safely be made. The main feeding pipe from the boiler, which has to supply several circulating pipes, should be no larger than they, unless more than 4 pipes are to be