CHAPTER XXX.

FUEL-COAL, WOOD AND CRUDE OIL.

The location and extent of the establishment will have much to do in determining what kind of fuel will be most satisfactory and economical.

The use of hard wood, in localities where it is plentiful and where coal is dear, may be advisable, especially when flues are used, or in large establishments where a night fireman is employed. For small heaters in which coal is used, the nut anthracite will be preferable, and as the size of the heater increases, a choice must be made between the egg or pea sizes, and bituminous coal. Most of our modern heaters are made for either hard or soft coal, and the choice that is made will depend largely upon the cost of each. In large establishments some form of bituminous coal would probably be used.

When situated near the mines, some of the lowpriced grades of pea or slack coal will make cheap fuel, but they are not worth more than two-thirds as much as good lump coal, and as the freight and handling make up the principal cost of the former, when they have to be transported any great distance, the latter will be the cheapest fuel.

CRUDE OIL AS FUEL.

Various devices have been invented for the burning of crude oil in greenhouse heaters. This material can only be used when steam under a moderately high pressure can be used to vaporize the oil. In order to use it in a hot water heater, a small steam boiler will also be needed as an auxiliary. One of the best of these burners

(Fig. 128) is that patented by James B. Moore, of Reading, Pa., which consists of an oil tube with a tapered nozzle, surrounded by a steam pipe also with a tapered nozzle. The combustion chamber is of solid metal and is placed in the ash pit, the grate having been taken out. The air for combustion is admitted through openings on three sides of the base of the boiler. The burner is inserted through a hole on the fourth side, and is surrounded by a conical tube through which the air for combustion enters.

The oil tube is connected with the oil tank, and the steam pipe with the steam dome, and also with an air

STEAM

AIR

OIL

FIG. 128. CRUDE OIL BURNER.

pump, by which a blast is supplied while getting up steam. The steam pipe does not go directly from the dome to the burner, but first makes a circuit of the combustion chamber, and the steam is there superheated. In passing through the tube to the nozzle, the oil, being surrounded by the superheated steam, is considerably heated, and flowing through the spiral grooves in the

valve escapes from the nozzle, but is at once vaporized by and mixed with the steam. It is thus carried into the combustion chamber, and may be scattered by a deflector. While a pressure of steam of from ten to fifteen pounds is desirable, the burner will give a perfect combustion of fuel with eight pounds, and even less.

In the past many persons have been prejudiced against the use of crude oil as fuel, on account of the offensive odor given off when it is handled, and from the many fires and explosions that have occurred from its use. Crude oil cannot be used to advantage unless a pipe can be run from the greenhouse to a large iron tank in which the oil is stored. This tank must be several hundred feet from any building, and so situated that it can be readily connected with a tank car on a side track. In this way there will be but little odor. The oil, by opening a valve, will run down hill to the greenhouse, and if the joints are all tight there will be no danger from explosions. The burners will require but little attention, there is no stoking to be done, no ashes to be carried out, and there will be no dirt and smoke to annoy one.

About one hundred gallons of oil will be equal to a ton of Anthracite pea coal, and making allowance for the extra labor required when coal is burned, it is gen. erally estimated that with oil at $1.25 per barrel, it will be as cheap as soft coal at $1.80 per ton, and although the relative price may vary, the usual opinion is that with a good burner the oil is about twenty-five per cent cheaper than steam lump coal.

GAS AND GASOLINE.

Natural gas has been used with good results, but it cannot always be relied upon, and the supply is ●ven now giving out in some places, while the limited terri tory in which it is found precludes its general use.

Water gas is found in many places to be an economical heating material. It costs only about twenty-five cents per thousand feet, and at that price is less than one-half as expensive as coal, and is regarded by many as cheaper than natural gas at current prices. While it may come into general use in cities, few florists are so situated that they can obtain it except at a considerable expense for the laying of mains, and it has not as yet been thoroughly tested for greenhouse heating. Gasoline can be readily handled, and florists are now looking to it as a valuable source of fuel. When a burner adapted for its use has been invented, it may revolutionize our present heating plants.

INDEX.

Achyranthes, varieties of...... 276 Carnations, care of the house