the machine is dependent on the arrangement and amount of carbide placed in the generator. Carefully guard against the escape of gas.

Whenever recharging with carbide always replenish water supply.

Never deposit residuum or exhausted material from water feed machines in sewer pipes or near inflammable material.

Water tanks and water seals must always be kept filled with clean water.

Never test the generator or piping for leaks with a flame, and never apply flame to an outlet from which the burner has been removed.

Never use a lighted match, lamp, candle, lantern or any open light near the machine.

The failure to observe the above cautions is as liable to endanger life as property.

CANDLES should be placed in heavy bottomed candle holders, in order to keep them from falling over, or, they should be placed in lanterns. The latter way is preferable. They should never be carried around among loose inflammable materials where they are apt to come in contact with them, and should never be used outside of lanterns where there is any flying inflammable materials. The use of candles outside of lanterns is to be held as being dangerous.

COAL GAS.-Where there is a private system of production, the burner or furnace house should be detached from all other buildings, and preferably be built of skeleton iron frame, i. e., an open-sided iron shed.

(ELECTRIC LIGHTING.-See Chapter V.)

GASOLENE VAPOR GAS LIGHTING MACHINES, LAMPS AND SYSTEMS-(National Board of Fire Underwriters):

Class A.-Machines having outside carbureters. These machines, which do not introduce liquid gasolene into the building, are regarded from an insurance viewpoint as constituting the least dangerous type of gasolene gas machine.

These ma

Class B.-Machines having inside carbureters. chines are regarded from an insurance viewpoint as more dangerous than those having outside carbureters, owing to the fact

that they introduce gasolene in liquid form and manufacture gas inside the building. Where permitted the following rules and precautions should be rigidly observed.

Class C.-Gasolene oil distribution systems. These systems are regarded from an insurance viewpoint as more dangerous than the systems in Class A or Class B. Where used their hazards should be recognized by underwriters and the following rules and precautions should be rigidly observed,

Class D.-Gasolene vapor lamps. These lamps are regarded from an insurance viewpoint as even more dangerous than the systems covered in Class A, Class B or Class C, and where used their hazards should be recognized by underwriters in higher rates of premium.

Class E.-Especially hazardous systems. Gasolene vapor gas lighting machines or systems in which any of the following defects are inherent or in which the hazardous conditions which they represent are likely to obtain, introduce especially dangerous features which cannot be measured by any obtainable rate: I. Machines which have no automatic control over either the quantity or quality of the gas supplied. 2. Systems in which it is possible to admit at one time more than one gallon of gasolene inside the building. 3. Machines in which a flame is used to vaporize gasolene. 4. Systems in which sheet metal piping is used to distribute gas. 5. Machines or systems in which air is drawn into the open end of the service pipe, as in a Bunsen burner. 6. Machines which require hand regulation as the number of burners in use is varied.

GASOLENE VAPOR GAS (National Board of Fire Underwriters). Where there is an outside carbureter it must be at least 30 feet from any building, below the frost line and below the level of the lowest pipe in the buildings lighted; the blower must be set on a level foundation, with the weights so arranged, when weight-driven blowers are used, that they may be wound up at any time without affecting the pressure on the lights; must be automatic in action; the mixers must have no open connection to the outside air except through the blower; the pressure regulator must not depend upon springs for proper action. The piping from the carbureter to the building must not be located near, nor placed in the same trench with other piping;

must have an incline toward the carbureter of not less than I inch in 10 feet, must be laid on solid earth below the frost line and not on wooden blocks or sticks; fill, vent and transfer pipes extending to the surface of the ground must be boxed or provided with enclosing sleeves to prevent the freezing of the earth about them; openings for pipes through outside walls must be securely cemented and made water tight. The inside piping must incline in all cases toward the main riser, hence all horizontal branch pipes should rise from the floor below and not descend from the ceiling above, and in no cases must there be any sags, pockets or traps in the pipe; the air pipe from the pump must be carried at least 24 inches higher than the top of the filler pipe of the carbureter.

The following schedule of pipe sizes for gasolene vapor gas is advocated:

No riser in any building should be less than I inch inside diameter.

For branches the following table gives the proportionate sizes and lengths of branches:

No pipe used in any portion of the building, even though it is only to supply one light, should be less than 3%-inch inside diameter.

GASOLENE VAPOR GAS (National Board of Fire Underwriters). Where there is an inside carbureter the supply tank must be located outside of the buildings, and wherever possible at least 30 feet from all buildings, and below the level of the lowest pipe in the buildings in the system; where it is not pos

sible to bury the tank it can be located in a non-combustible building or vault, properly ventilated; the fill and vent pipes must terminate in an iron box, cover of which should be flush with the ground and locked with a padlock. The carbureter must not contain more than one quart of gasolene at any one time, must have no valves opening into the room, must be provided with an overflow connection draining back to the supply tank; only hot water or steam to be used to produce rapid evaporation, and, in all cases, the heating and evaporating chambers must be entirely separate. Single plunger gasolene feed pumps must have a check valve as close to the pump as possible. The pipe connecting the supply tank and the carbureter must incline toward the former at least 1 inch in 5 feet, and this pipe must be at least one size larger than the supply pipe. All the other piping must be in conformity with the rulings under the outside carbureter system. A filler must be provided in the gasolene supply pipe as near the pump as possible, and accessible for the purpose of cleaning; a substantial flange fitting containing fine brass gauze is recommended for this purpose.

GASOLENE OIL DISTRIBUTING SYSTEMS.-The tanks and reservoirs must be located as per rulings for tanks where an inside carbureter is in use, and must be so arranged that under normal conditions the only gasolene in the building will be that contained in the pipe system and so that under no possible condition can more than one gallon of gasolene be accidentally admitted at one time within the building, and must be so placed that no artificial light will be required while filling, and must be provided with a pressure gauge and a shut-off valve. The distributing tubes must be run in wooden moulding or iron pipes inside of a building, and must not be held in place with staples; must not be concealed behind walls or ceilings, must not be nearer than 3 inches to electric wires, and where tubes cross wires, pipes or metal girders proper insulation must be provided. In order to control the supply of gasolene to all of the lamps on each floor and to each lamp, readily accessible shut-off valves must be provided. The lamps and burners must not be used in places where an undue amount of ignitable material may accumulate on them, or where there is inflammable dust or gas, or where there is loose inflammable material on the floor under

them; must not be initially heated by the use of liquid gasolene, and in all cases they must be suspended from a rigid and secure support not liable to become weakened by vibration or continued use; must be of such length that the distance from the burner gauze to the point of support shall not be less than 20 inches, and must in all cases be provided with a metal heat deflector permanently secured to the frame.

GASOLENE VAPOR LAMPS.-The distance between the burner gauze and the top of the frame must not be less than 20 inches. For gravity lamps the reservoirs must not exceed two quarts capacity, and must be provided with a conspicuous filling indicator to show when the reservoir is nearly full. For pressure lamps the reservoirs must be so arranged so that not to exceed two quarts of gasolene can be supplied. The generators must have all parts accessible for purposes of cleaning. Shut-off valves must close against the gasolene supply. Metal heat deflectors must be attached to all pressure-feed lamps and to all gravity-feed lamps, and fixtures in which the distance from the burner gauze to the top of the frame is less than 30 inches, or in which the distance between the edge of the reservoir and the vertical center line of the generator is less than 6 inches; they must not be less than 4 inches in diameter, and must be secured in a substantial manner so as not to be readily removed. KEROSENE OIL PRESSURE SYSTEMS-(National Board of Underwriters).—These systems used to supply kerosene vapor lamps, stoves, blow-torches and furnaces with oil under considerable pressure are regarded from an insurance viewpoint as much more hazardous than ordinary kerosene lamps or stoves. Where used, the following rules and precautions should be rigidly observed:

The supply tank should preferably be located outside, under ground and below the lowest level of the pipes in the building connected with the apparatus, but if inside of the building it must be in such a location that no artificial light will be required while filling it, and so arranged as not to be exposed within 15 feet of any stove or furnace; must be provided with a reliable pressure gauge, a shut-off valve, an air relief valve, and a fusible device to vent tanks in case of fire. Must not be used with an operating pressure of over 100 pounds per square inch, and must