eted by their vertical and horizontal legs to the sides, top and bottom of box girders for strengthening their angles. GROCERS, RETAIL-Good insurance if well established. GROCERS, WHOLESALE-Losses in this class are heavy and are regarded by most companies as unprofitable. There may be spice grinding, coffee roasting, bottling of salad oils, ammonia or vinegar, considerable excelsior for packing material and storage of large quantities of matches. See Canned Goods.

GROIN-An arch formed by two segmental arches or vaults intersecting each other at right angles.

GROOVED-AND-SPLINED-Planks grooved at both edges instead of being tongued and grooved. When laid, a strip, called a spline, is driven in between the planks, which takes the place of tongue.

GROUND (Made Ground)-Cinders from smelting furnaces or others which contain a large percentage of unconsumed coal should not be used for filling under buildings. The Tottenville Copper Co., Staten Island, suffered a loss of approximately $20,000 on April 14, 1910. Fire was discovered near the melting furnaces and was probably started by hot coals finding their way through a crack in the bottom of pot melting furnaces or flue and thereby coming in contact with the unconsumed coal in the cinders of which the filling under the floor of the building was composed. N. Y. Board of Underwriters.

GROUT-The mortar poured into the interstices between stones or bricks.

GUANO (manure)—If moist and piled deeply, is liable to cause spontaneous combustion. Although the hazard is very mild, inspectors should always suggest that pigeons and chickens be removed from the attics or cupolas of buildings.

GUARDS—During war times and strikes, when incendiaries are active, the question of sufficient armed guards plays even a more important part than the construction of the building and the hazards contained therein. The year 1917, with its heavy loss record, shows that many plants were not properly guarded. See War Conditions.

GUAYULE-A form of rubber.

GUTTA-PERCHA

GUESTS-See Servants.

GUMS-Nearly all kinds are imported in bags.

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GUNCOTTON-Cotton soaked in nitric and sulphuric acid mixture. The stronger the nitric, the more powerful the guncotton. A weak solution produces collodion or celluloid. See Nitro-cellulose.

GUN METAL (or Bronze)-A compound of copper and tin.

GUNPOWDER-A mixture of potassium nitrate or saltpetre, powdered charcoal and sulphur. The explosive quality of gunpowder is due to the fact that it will burn with great rapidity without contact with air and that in burning it liberates large volumes of gas.

GUNNY-A coarse, heavy fibre wtth a satiny lustre. A specie of jute or hemp. Used principally for bagging. Empty bags which have contained oily substances or oil products should not be stored in piles as spontaneous combustion may result.

GUNSMITHS-Foundry hazard and extensive machine shop with plating and buffing, also wood working. Considerable oil and grease is used to prevent the guns from rusting, low grade vaseline being used extensively. When fixed ammunition is loaded, such work should be in a separate building. Fair insurance risks.

GUTTA-PERCHA—Gutta-percha is rubber. When in sheets, steam-heated mixers and calenders are used. When mixed, beeswax is added to keep the gutta-percha from sticking to the rollers, and oxide of iron and oxide of zinc are also added. The sheets are sprinkled with talcum powder to prevent adhering when rolled up. Hazard is mild.

GYPSUM is sulphate of lime found in rock formation. It is a slow conductor of heat, as it contains in its mass a multitude of infinitely fine air cells. Gypsum manufacturers claim that three inches of gypsum properly applied to steel or ironwork will hold the temperature of the metal to about 300 deg. F. when exposed to 2,200 deg. F. for a period of four hours.

GYPSUM ARCH (Fire Test)—A 4-inch panel flat arch of gypsum and shavings reinforced with Clinton Wire Cloth,

two inches cinder concrete fill on top and soffit of arch covered with 11⁄2 inches of plaster, 1 part cement and 3 parts composition plaster. Span of arch 5 feet 3 inches to center of I beams. Furnace of 12-inch concrete, interior about 9 feet above grating on which the fire was placed. Heat averaged 1,700 degrees for 4 hours. The gypsum arch surprised those in charge with its unexpected strength. The arch had been in place about two weeks. After the test the arch was intact except that wire mesh reinforcement was exposed where water from hose stream washed the plaster off, about 3 inches remaining showed result of calcination; the lower flanges of I beams were exposed. The sawdust appearing in arch is natural in color, showing heat did not penetrate through arch further than one-half inch. No load test was applied.

Water Application-At intervals of 5 minutes the following was applied: 21⁄2-inch hose with 1%-inch nozzle, 100 pounds pressure at hydrant. First, stream of one minute duration at each of two doors to quench fires, one minute streams on arch, outside flushed for one minute, hose applied three times to interior of furnace to cool and wash down. GYPSUM PLASTER MILLS-Reduce gypsum to the finest possible powder or flour before passing it to the cookers or calcining kettles and then to apply only such degree of heat as will serve to carry off such proportion of its contained moisture as will prevent the voluntary setting or hardening of the finished material when exposed to the atmosphere. Inspect carefully before binding lines.

H

HAIR-Human hair stocks are not considered desirable, owing to susceptibility of stock.

HAIR BRISTLES-See Bristles.

HAIR CURLERS are made of piece or scrap leather, cut and sewed with a cotton filling through which runs a wire. Hazards are storage and sorting of scrap leather into which considerable quantities of rubbish find their way; sewing machines, storage and use of cotton batting or tow. Usually untidy appearance.

HAIR-DRESSERS-Use alcohol for massage purposes, and in lamps for curling irons, electric hair dryers, also gas-heated hair dryers. for cleaning hair goods and also make premises. Fair risks.

curling irons and Some use benzine cosmetics on the

HAIR FABRIC as used for nets or braid. The hair is reduced to a paste by a solvent, run through an artificial silk spinner and drawn out in threads. Can be braided or woven like horse hair.

HAIR GOODS—Manufacturing-The hair is washed in hot water with or without disinfectant, bleached (usually with peroxide of hydrogen), dried in dry room, curled on irons, hand combed, or dyed. Use aniline dyes, muriatic and sulphuric acids. Highly susceptible. See Dry Rooms, also Bleaching.

HAIR NETS are made by hand from Chinamen's queues or from combings of women's hair.

HAIR ORNAMENTS are usually made of celluloid, ivory, imitation ivory, vegetable ivory or bone. Involves hazards of celluloid working on power machinery. See Celluloid. HALIDES are a group of elements including fluorine, bromine, chlorine, and iodine.

HALLS-Buildings used for halls and lodge rooms are

usually of large, open area; either frame or ordinary brick construction with unprotected floor openings. May have miscellaneous stores on ground floor. The hall proper usually has a complete stage equipment; the stage constructed of wood or other light material; makeshift dressing rooms and an abundance of old properties and scenery which accumulate and are rarely ever removed. The dance floor is highly polished, and care should be exercised in storing of oil and floor mops. Gangsters frequent the poorer class halls. Many fires are caused by smoking. Usually someone during the evening drops a lighted cigarette or a cigar butt in some obscure corner, which smolders and during the early morning hours finally breaks into flame. Fires once started in this class are hard to extinguish. Poor fire record.

HALOXYLINE-A form of gunpowder.

HALVING-To notch together two timbers which cross each other so deeply that the joint thickness shall only equal that of one whole timber.

HANDKERCHIEFS-Fancy handkerchiefs are mounted on colored pasteboard which, when wet, may stain and thereby reduce the value of the goods. The manufacturing consists of cutting, sewing, hemstitching and ironing. Classed as white goods manufacturing. The nature of the business requires cleanliness.

HANGARS-Usually high one-story light frame structures used for housing airplanes. Mechanics and others frequently smoke here and throw oily waste about. Gasoline in cans is sometimes found. A poor fire record class as they are nearly always located in sparsely settled places without fire protection. Interior protection is essential. (S. T. Skirrow.) HANGERS-Fixtures projecting below a ceiling to support the journals of long lines of shafting, or piping. HARD COAL is almost wholly composed of carbon. HARDENING AND TEMPERING-Known as Heat Treatment Process in machine shops; consists of hardening and tempering tool steel. The steel is first placed in gasheated hardening ovens until a certain temperature is reached and then plunged into an oil trough with agitator. The oil used is principally fish oil, flashing at about 550 deg. F. Care