UNIVERSITY OF CALIFORNIA PUBLICATIONS COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY,- CALIFORNIA FIRE PROTECTION FOR GRAIN FIELDS WITH SPECIAL REFERENCE TO FIRE PROTECTIVE APPLIANCES FOR GRAIN-HARVESTING MACHINERY BY WOODBRIDGE METCALF A thousand acre grain fire. BULLETIN No. 295 May, 1918 UNIVERSITY OF CALIFORNIA PRESS BERKELEY 1918 Benjamin Ide Wheeler, President of the University. EXPERIMENT STATION STAFF heads of divisions Thomas Forsyth Hunt, Director. Edward J. Wickson, Horticulture (Emeritus). Herbert J. Webber, Director Citrus Experiment Station ; Plant Breeding. Hubert E. Van Norman, Vice-Director; Dairy Management. William A. Setchell, Botany. Myer E. Jaffa, Nutrition. Charles W. Woodworth, Entomology. Ralph E. Smith, Plant Pathology. J. Eliot Coit, Citriculture. John W. Gilmore, Agronomy. Charles F. Shaw, Soil Technology. John W. Gregg, Landscape Gardening and Floriculture. Frederic T. Bioletti, Viticulture and Enology. Warren T. Clarke, Agricultural Extension. John S. Burd, Agricultural Chemistry. Charles B. Lipman, Soil Chemistry and Bacteriology. JClarence M. Haring, Veterinary Science and Bacteriology. Ernest B. Babcock, Genetics. Gordon H. True, Animal Husbandry. James T. Barrett, Plant Pathology. Fritz W. Woll, Animal Nutrition. Walter Mulford, Forestry. W. P. Kelley, Agricultural Chemistry. H. J. Quayle, Entomology. J. B. Davidson, Agricultural Engineering. Elwood Mead, Rural Institutions. H. S. Reed, Plant Physiology. W. L. Howard, Pomology. fFRANK Adams, Irrigation Investigations. C. L. Roadhouse, Dairy Industry. O. J. Kern, Agricultural Education. John E. Dougherty, Poultry Husbandry. S. S. Rogers, Olericulture. R. S. Vaile, Orchard Management. J. G. Moodey, Assistant to the Director. Mrs. D. L. Bunnell, Librarian. DIVISION OF FORESTRY Walter Mulford Charles H. Shattuck JDavid T. Mason JDonald Bruce Woodbridge Metcalf $ In military service. t In co-operation with office of Public Roads and Rural Engineering, U. S. Department of Agriculture. FIRE PROTECTIVE APPLIANCES FOR GRAIN-HARVESTING MACHINERY By WOODBRIDGB METCALB California's grain crop for 1918 has assumed an importance in the present emergency far greater than even the large figures suggest. These show that cereal crops occupy nearly two million acres of land, or approximately 30 per cent of the total improved acreage in the state. Their estimated value is about a hundred million dollars. Fig- ures, however, do not suggest the proper basis for valuation of this crop. It can best be interpreted in terms of food for a world which needs it as never before. Because of world shortage someone is dependent upon every bushel of grain which can be grown and har- vested. The loss of even a small quantity means that someone who is deprived of it will have to go hungry. The farmers have responded splendidly to the call by putting in what promises to be the largest crop of grain raised in many years. This, however, is not enough. They must take all precautions possible to prevent losses of all kinds, in order that the maximum amount may be delivered and put to effective use. In the past fires have caused very serious losses to the grain crop. So serious in fact have these been that in spite of insurance rates which are twice as high as those in "Washington and Oregon, many fire insurance companies have considered refusing to take grain risks until conditions show improvement, because of the excessively high loss ratio. Tf their estimate of loss of grain in California amounting to $250,000 a year for the past few years is translated into present values, loss of a similar amount of grain this year will involve a damage over twice as great. At 50c per man per day this loss would feed 10,000 of our boys in France for over three months, and if only the cereal ration is considered the grain thus destroyed would supply this number of men for nearly three years. It is, therefore, evident that each one of us should consider it a patriotic duty to adopt such necessary precautionary measures as will cut this loss down to the absolute minimum. 352 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION CAUSES OF FIRES It has often been said that four out of every five fires are prevent- able, and grain fires seem to be no exception to this rule. In an attempt to discover the cause of these fires every insurance company doing business in the state was asked for data on their losses during the past three years. Replies were received from twelve companies, reporting on a total of 260 fires as follows: Causes of Grain Fires in California, 1915-1917 No. Per cent Unknown 79 30.3 Harvesting machinery 78 30.0 Eailway 28 10.7 Miscellaneous 27 10.4 Carelessness 21 8.1 Smoking 20 7.7 Incendiary 7 2.8 260 100.0 Fi g- 2.— A centrifugal air clarifier. Air enters through pipe (c), dirt is dropped and collects in Mason jar (b), clean air goes to carburetor through pipe A, all joints of which should always be kept tight. FIRE PROTECTION FOR GRAIN FIELDS 353 The average loss per fire paid was found to be $1515, and even when one very large loss from Imperial County is disregarded, the average loss is well over $1000. This, of course, represents the amount paid by the companies, which probably is not over 75 per cent of the value of materials actually destroyed. It seems, therefore, reasonable to assume that if the average fire causes a loss of from $1000 to $1500, the grain man is certainly warranted in expending an amount at least equal to 6 per cent of the probable damage in order to prevent that fire or extinguish it quickly if it starts. A study of the above table shows that grain harvesting machinery is responsible for 30 per cent of the fires, being by far the most im- portant known cause. The other causes are being attacked in the most effective way possible, and it is believed that by education of the public to the dangers involved, most of the fires in the "miscel- laneous," "carelessness" and "smoking" classes can be eliminated. The railways are cooperating in an effort to cut down preventable fires along their rights-of-way. The incendiary must be watched and brought swiftly to justice. The following rules were followed last year in Washington with good results: "Forbid strangers access to any part of your premises with- out proper credentials, no matter what the pretext. Employ no one in any kind of service whom you do not know to be reliable and above suspicion. Report to proper officials anyone found lurking about your premises. Do everything which suggests additional safety against loss or damage from known causes and all unknown causes which clever or unscrupulous enemy sympathizers, spies, or the ordinary cranks, stimulated by unusual conditions, are liable to think of or devise." SAFEGUARDING HARVESTING MACHINERY Fires set by harvesting machinery are the result of several well- defined causes, all of which can be largely eliminated by the adoption of proper precautionary measures. These causes in their relative order of importance are as follows : 1. Hot carbon from the exhaust of tractor or auxiliary engines. 2. Hot boxes in any of the moving parts. 3. Ignition of straw or chaff in contact with exhaust pipes and manifolds. 4. Ignition or explosion of dusty or smutty grain by static elec- tricity sparks. 5. Sparks caused by gravel, matches, or foreign matter getting into the separator. 354 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION CAEBON Carbon results from imperfect combustion of fuel, the residue from the lubricating oil, and from dust drawn into the cylinders with the air. It collects there, and is expelled in flakes or chunks through the exhaust in an incandescent state and sets a majority of the fires attributed to harvesting machinery. To control these sparks effect- ually is to prevent probably 75 per cent of the machinery-caused fires in grain. AIE CLAEIFIEES Chemical analysis of carbon has shown 43 per cent of it to consist of field dirt and dust. This not only adds to the fire menace, but scores out the inside of the cylinders to a very appreciable extent. So true is this in dusty weather that Professor Davidson states it to be a mechanical crime to operate a tractor under dusty conditions with- out a clarifier. Fig. 3. — The vacuum bag air clarifier. Air enters through pipe and against baffle plate (A), is strained through canton flannel bag (B), which catches all dirt and passes out the top through pipe (C) to the carburetor. FIRF, PROTECTION FOR GRAIN FIELDS 356 Clarifiers are of two kinds, the centrifugal and the vacuum bag. The air is either rotated or passed through a canton flannel bag, so that all solid matter which it may contain is removed before it enters the carburetor. Clarifiers are now installed on all tractor and har- vester engines and should be considered an absolute necessity during harvest time. The pipe leading from the clarifier to the carburetor should be carefully inspected each day to see that the joints are tight. If there are leaks, much dirt-laden air will be taken in and the efficiency of the device impaired. SPARK ARRESTERS In spite of the use of a clarifier there will always be some carbon coming from the exhaust which must be caught and held in some effective manner if we are to eliminate fires. All of the larger Fig. 4. — The old conical type spark arrester is entirely ineffective in stopping sparks. Gases are concentrated at the apex which has often burned out or blown off while red hot. The use of this arrester in harvest fields should be discontinued. machines have been equipped with so-called spark arresters in tin' past, but the types in use up to this time have given very poor pro- tection for the following reasons : 1. They are built on the wrong principle, as in the conical type which concentrates the gases at the apex instead of dispersing them. In several cases bad fires have been caused by the apex of the cone blowing off into the grain while red hot. 356 UNIVERSITY OP CALIFORNIA — EXPERIMENT STATION 2. The mesh of the screen is too coarse, allowing sparks to pene- trate and so set fires. 3. In many cases carbon and rust have collected in flakes on the outside of the arrester to be blown off when a particularly strong explosion comes. 4. Under certain conditions, particularly with an excess of fuel or lubricating oil, the exhaust gases become ignited on the outside of the screen and will flame like a torch for several minutes. This condition is particularly dangerous in windy weather. Pig. 5. — An assembled Harris spark arrester and its component parts. It is simple, easy to keep in repair and if kept clean has given good protection from sparks where used on auxiliary engines. If larger area of screen is desired the separators and bolts can be lengthened. The Yuba tractors will hereafter be equipped with arresters of this design. In an endeavor to have these things corrected at the source in so far as possible, the tractor and harvester manufacturers of the state were visited and the importance of the matter placed before them. Excellent cooperation was secured from all of the companies, who at once set out to devise better protective devices for their particular machines. New machines are being equipped with these and owners can secure the new equipment for old machinery from the respective companies or their regular local agents. The Best Gas Traction Company, San Leandro, has adopted a new double screen arrester with heavy top and bottom castings instead of the old conical type. The Yuba Manufacturing Company, Benicia, and the Harris Man- ufacturing Company, Stockton, have adopted arresters of simple and almost identical design, consisting of heavy top and bottom castings held together with three bolts and grooved on the edges. Double thickness of window screen is tightened into these grooves by means of a double strand of baling wire. The screen if worn can be replaced in a few minutes, the only requirements being the screen, baling wire, and a pair of pliers. These will give reasonably good protection if FIRE PROTECTION FOR GRAIN FIELDS 35"3 the screen is whole. They should be brushed off and the carbon shaken out of the inside at least once a day. Under very dangerous conditions it may be necessary to cover them with a larger screened cylinder of the Hahn type. The Holt Company of Stockton has developed a centrifugal type of arrester built on a principle similar to that of the clarifier. The gases are revolved by means of a baffle plate which throws down any solid particles of carbon and allows the gas to pass out. Its parts are all of cast iron so that there is no screen to burn out, while the amount of back pressure is said to be negligible. From preliminary tests this promises to be a very satisfactory device. Two handfuls of sawdust were recently thrown into the carburetor of a machine equipped with this spark arrester. As far as could be determined none of it got through and the residue was found trapped in the device when the cover was removed. It is hoped that field tests will show it to be as satisfactory a device as was indicated by its initial performance. HOME-MADE SPARK ARRESTERS While in general a home-made device is apt to be less perfect than one built for the machine at the factory, several men have developed spark arresters which have furnished the required protection. Sec- ondary screens have generally been box-like in shape, with one to several layers of window screen, and have been used as an added protection around the regular spark arrester. When built with square corners and screen top they are open to the objection that chaff and straw may settle on the top, or in a high wind collect on the windward side. Here it is apt to be set on fire from the heat and blow off into the grain when the direction of the machine is changed. If the outer screen is not large enough, explosive gases often collect in it and then burn on the outside of the screen. The most satisfactory device of this kind is the screened cylinder used by Hahn Brothers of Arbuckle. This, as shown in the picture, is a cylindrical frame 24 inches in diameter and 24 inches high, built of 1-inch strap iron, the six uprights being riveted to top and bottom hoops. The top and bottom are solid, made of No. 16 galvanized iron turned up at the edges to fit over the hoops to which they are fastened with stove bolts. The bottom should be fitted tightly around the exhaust pipe which can be accomplished by cutting a hole the exact size of the pipe out of the center of a tin pie plate. The plate can be forced over the pipe after the bottom of the cylinder is in place. 358 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION The sides should he covered with a double thickness of window screen fastened to the frame with light wire. The cylinder is held rigidly to the top of the cab by four long 3/ 8 -inch bolts passing through two strap iron pieces on the top and tightened up by means of thumb nuts on the under side of the canopy supports. It will be convenient to have a small opening in the top, closed by a sliding door which should fit Hxj&eScretm JparA Arres ter 7Sf1r^2/-rKhLot//'' WATER JACKET 9PARK A/tffEJTf/? DesiqneoL 6y Geo. £"///£ hhfvr //>£, Fig. 8. — The water jacket arrester provides great safety under careless or inefficient operation of the engine. It does not have to be brushed off daily in order to be effective and the opening is so far removed from the engine that it is practically impossible to make it flame when using an excess of lubricating oil. In setting up the water jacket the tank is usually set on the running board to which it is fastened by two long %-inch rods, each being fitted with a hook at one end and a thread and nut at the other. The upper end is hooked over the top of the tank, the lower passing through the running board on the under side of which the nut is tightened up. To give added rigidity a piece of 2-inch plank is shaped to fit the curve of the tank, clamped to it by means of an iron band and bolted to the radiator platform. The top of the tank should be well above the canopy in order that the poisonous exhaust gases will not blow back in the operator's face. If a short boiler is used an FIRE PROTECTION FOR GRAIN FIELDS 361 extension of sheet iron can be riveted to the top into which a slot should be cut on the side toward the engine. The curved exhaust pipe can rest in this slot which will prevent its jarring loose. Only a few inches of water in the bottom of the tank are necessary though it is well to put in a foot or two in the morning as the loss through exapora- tion will exhaust from three to five gallons a day. Fig. 9. — Detail of Holt engine showing air clarifier and connections. The exhaust pipe and manifold are danger points as they become exceedingly hot. A sheet iron shield is being supplied to enclose these. The old type spark arrester shown in the foreground proved to be ineffective under dangerous conditions and has been discarded in favor of the centrifugal type. The water jacket arrester is open to several serious objections: (1) It is bulky and weighs upwards of 250 pounds without the water. (2) It is expensive, costing from $30.00 to $50.00, depending on local conditions. 362 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION (3) It turns the exhaust gases through two right angles which causes some back pressure and consequent heating of the engine. (4) If the carburetor acts slowly or one cylinder is missing the unburned charge of gas is apt to explode in the pipe. This seems to be a rare occurrence, however. (5) When installed on a machine with double exhaust pipes a pipe should lead from each of them to the water tank. People who have used this device consider that these disadvantages do not outweigh the big advantage of securing perfect control of hot carbon sparks. Fig. 10. — Detail of Best engine showing air clarifier attached to flat top stove. The double exhaust pipes are cooler than a single one, but the flat top of air heater (H) is a danger point for the protection of which a conical shield is now being supplied. Protection for exhaust pipes and manifolds has been provided by each of the companies. This will be accomplished by means of sheet- iron shields made in two parts. These can be slipped on and bolted in a few minutes and will completely enclose these parts of the machine giving an air space all around of about an inch. Use of these shields is particularly advisable in localities having peaty soils. Dust FIRE PROTECTION FOR GRAIN FIELDS )5().'{ from this soil is apt to collect on exhaust pipes before they become heated, taking fire later and blowing into the grain while burning. Owners of machines can procure these shields, as well as the new spark arrester, either from the local agent or from the factory direct. Static electricity frequently causes fires in very dusty or smutty grain where some of the moving parts of the separator are insulated from grounded parts of the machine by oil in the bearings. The electric charge collects on these parts until it is of sufficient intensity to jump to a grounded part of the machine which is accompanied by a blue spark of greater or less intensity, depending on the charge. This can be obviated in the case of a stationary machine by connecting all such parts to a wire which is in turn driven into a moist spot in the ground. This has not been an important cause of fires in Cali- fornia, but is very dangerous where smutty wheat is being harvested. For detailed wiring plans and discussion of this subject, see (1) and (3) under "Literature." OTHER SAFETY MEASURES Smoking should be discouraged at all times in the harvest field. Many men believe in prohibiting it entirely and will immediately discharge any man who smokes. If allowed it should only be at stated times, as after lunch, when the machinery is not running and when the men are in close proximity to the machine where fire extinguishers are instantly available. Giving up tobacco except under these conditions is a small discomfort in order to insure the safety of food supplies which may be destroyed by a fire. Matches dropped into the separator have been the cause of more than one fire and great care should be taken, particularly in the case of stationary outfits. It will be found advisable to furnish safety matches to all the men and prohibit their carrying the ordinary "parlor" match into the field. Safety matches must be struck on the box and do not constitute a menace if dropped carelessly. After extinguishing, always hold a match until it is cold or break it in two before throwing it away. Friction, which causes hot boxes as a result of improper lubrication or defective alignment of running parts, is an inexcusable cause of fires because with proper precautions it can be eliminated. Gravel, chunks of earth, or even large weed stems, sometimes cause fires because of friction sparks in the separator. Care should be taken to exclude all foreign matter of this kind. In some very stony fields fires have been set by friction sparks ; the result of wheels or treads 364 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION slipping off from flinty rocks. Extreme watchfulness and a good fire extinguisher are the best safeguards when working in a field of this character. '■ '|*J FIRE FIGHTING EQUIPMENT In spite of the best laid prevention plans some fires will un- doubtedly start. When this occurs equipment should be at hand to extinguish them and every man in the threshing crew should be drilled beforehand so that he will know exactly what to do and how to do it. Many disastrous fires have occurred in the past because nothing was at hand to fight them with when they started. Fire extinguishers should be considered an absolutely essential part of every harvesting outfit. The 2V2-gallon warehouse type acid- and-soda extinguisher is the most effective weapon for fighting grain fires when used properly. It needs only to be turned bottom side up to begin working, and will throw a stream of water about forty feet. A single charge lasts one minute and when used properly will wet down from two to three hundred feet of fire in standing grain. A box containing a few extra charges should be kept on the machine. One charge consists of one and one-half pounds of bicarbonate of soda (baking soda) and a four-ounce bottle of sulphuric acid. The soda should be thoroughly dissolved in the water so that no particles are left which may clog the hose. The acid is placed in a bottle held in a rack in the top of the extinguisher. The bottle has a heavy loose stopple which falls out when the device is reversed, allowing the acid to run into the other solution. The resultant chemical action sup- plies the pressure for throwing the stream of water. Two of these extinguishers with a half-dozen extra charges and a bucket for dis- solving the soda will enable a couple of men to extinguish almost any fire in its early stages. A list of these extinguishers approved by the National Board of Fire Underwriters is given on page 366. Several of these makes are listed at about $18.00 each, but are subject to a 30 per cent discount in lots of one dozen, f. o. b. San Francisco or Los Angeles. Chemicals for extra charges can be purchased at local drug stores, and will cost from 30c to 50c each. It will be advisable to carry the extra charges of acid in bottles which are the same as that in the extinguishers. This will obviate the necessity of pouring the acid from one bottle to another, also preventing loss of bottles from crack- ing. When the extinguisher is used several times in quick succession with the single bottle, the chemical action heats up the glass, which is apt to fly to pieces when the cold water of the next charge hits it. FIRE PROTECTION FOR (J RAIN FIELDS 365 Yolo County Ordinance No. 95 requires that every harvesting outfit shall be supplied with three fire extinguishers of approved design. The acid-and-soda type is excellent for fires in grain, but is not very effective in putting out a fire in oil, gasoline, or distillate. For this the one-quart size hand extinguisher with double-acting siphon pump is very effective. These cost about $10.00 each complete, while the liquid for refilling (carbon tetrachloride) costs $1.50 per quart in cans. The price in lots of one dozen extinguishers is sub- ject to a S3y 3 per cent discount, f. o. b. San Francisco. The carbon tetrachloride liquid changes upon being heated into a heavy non- combustible gas which smothers the fire. OTHEE FIKE-FIGHTING EQUIPMENT A simple but very efficient piece of equipment with greater capacity than the fire extinguishers mentioned and at the same time more easily transported into inaccessible places is the man pack water bag and fire pump, developed last year by the "Western Forestry and Conservation Association. A water-proofed canvas bag holding from seven to eight gallons of water is fitted with shoulder straps like a regulation pack sack. A double-acting siphon pump worked by hand draws water from the bottom of the bag through a short piece of hose. The pump will throw a stream of water forty feet. This equipment costs about $8.00 and is highly recommended by the fire wardens of the Oregon Forest Fire Association who used it last year. These outfits may be purchased through the above association, address 525 Yeon Bldg., Portland, Ore. A box containing from six to ten sacks or pieces of burlap folded and kept moistened is an excellent thing to have at hand on the tractor or harvester. A couple of men using these can follow after one using an extinguisher and effectually put out any sparks which may remain. Earth, particularly if light and sandy in texture, is a good thing with which to fight fire. In order to use it one or two broad hoes and the same number of sharp-nosed shovels should be kept at hand. The hoe can be used in digging up a rough fire line if the fire is not traveling too fast, or a wet sack can be tie^ to the blade and pushed along over the edge of the fire. A rake can also be used for this purpose. A furrow turned up with a plow will often stop a small fire or make it safe to back-fire against a big one. If the fire has reached a stage where such measures are necessary it will probably be beyond the control of the threshing crew and need the services of the community fire-fighting organization to extinguish it. A back-fire 366 UNIVERSITY OP CALIFORNIA — EXPERIMENT STATION should be set with great care and only under the direction of a fire warden or the local fire boss. If started at the wrong place or time it may become more dangerous than the fire it was set to control. CARE OF MACHINERY In closing it may be said that the easiest way to avoid a fire is to prevent it. One of the simplest preventive measures is to keep the machinery in the best of repair at all times. Before commencing with the harvest go over the tractor and combine carefully to find and repair the minutest break or defect. See that all parts are in proper alignment and that worn bearings or gears are replaced. Pay par- ticular attention to lubrication of the machines, going at it sys- tematically with the idea that no spot will be overlooked. Use enough oil in the proper place, but do not allow excess to run over the machinery where it will collect grit and dust, and do not fill crank case too full. Be sure that the carburetor is adjusted to insure perfect combustion, the ideal being to give the motor as much air and as little fuel as it will handle to produce the recpiired power. Black or brown smoke from exhaust always indicates too rich a mixture. The exhaust gases should be colorless. Satisfy yourself bj' thorough tests at night when you can see sparks, that your spark-arresting device is giving 100 per cent protection and inspect it often enough to be sure that it maintains this standard. Systematic precautions beforehand may save you several hours' or days' loss of time during the rush of the harvest season when every minute counts. Follow the measures outlined in "The Six Rules," and adopt any others which may seem advisable in your particular case. SIX RULES FOR PREVENTION OF FIRE IN GRAIN FIELDS RULE ONE — Keep your machinery in repair, well lubricated and provided with an air clarifier and a good spark arrester. Hot boxes and hot carbon cause 30 per cent of grain fires. RULE TWO — Always have at hand on the harvester at least two good chemical ■fire extinguishers. They keep little fires from ' ' growing up. ' ' RULE THREE — Don't smoke in the fields. Tobacco may be satisfying, but it's "hot." RULE FOUR — Break up big fields by cutting hay strips at intervals while grain is green. These give you a chance to fight and confine fire to a small area. RULE FIVE — Ploiv several furrows around your grain field as a fire break. Your neighbor may not be as careful as you are. RULE SIX — Help organise your community and install fire fighting equipment at convenient points. Get ready now. After a fire starts it's too late. FIRE PROTECTION FOR GRAIN FIELDS 367 FIRE EXTINGUISHERS (List of companies manufacturing extinguishers which comply with requirements of the National Board of Fire Underwriters) Acid and Soda — 2%-Gallon — Loose Stopple Type American-La France Fire Engine Co., Elmira, N. Y. Badger Fire Extinguisher Co., Boston, Mass. Bentley Mfg. Co., The, E. A., St. Louis, Mo. Booth-Coulter Cooper and Brass Co., The, Toronto, Out. Boyd and Bro., Jas., Philadelphia, Pa. Buffalo Chemical Fire Extinguisher Co., The, Buffalo, N. Y. Childs Co., O. J., Utica, N. Y. Diener Mfg. Co., Geo. W., Chicago, 111. Garth Co., The, Montreal, P. Q. Harker Mfg. Co., Cincinnati, O. Knight and Thomas, Inc., Boston, Mass. McMorran Co., Edward E., Chicago, 111. Miller Chemical Engine Co., Chicago, 111. Missouri Lamp and Mfg. Co., St. Louis, Mo. Northern Fire Apparatus Co., Minneapolis, Minn. Pittsburg Lamp, Brass and Glass Co., Pittsburgh, Pa. Pyrene Mfg. Co., New York, N. Y. Eowe and Son, New York, N. Y. Racine Iron and Wire Works, Racine, Wis. Standard Extinguisher Co., The, So. Boston, Mass. Stempel Fire Extinguisher Mfg. Co., The, St. Louis, Mo. Victor Fire Extinguisher Co., Toronto, Ont. Western Inspection Co., Buffalo," N. Y. Hand Extinguishers — 1-Quart — Pump Type Electrene Co., New York, N. Y. "Fire Gun." Fyr-Fyter Co., The, Dayton, Ohio. Factory, Chicago, 111. ' ' Fyr-Fyter. " Johns-Manville Co., H. W., New York, N. Y. "J-M." Justrite Mfg. Co., Chicago, 111. "Justrite." Pyrene Mfg. Co., New York, N. Y. "Pyrene." The Board of Fire Underwriters of the Pacific give the following: as official San Francisco agents for approved fire extinguishers : American-La France Fire Engine Co., 151 New Montgomery St. Badger Fire Extinguisher Co., 507 Montgomery St. Boyd Bros. Co., c/o Paul Brant, 67 Main St. Childs and Co., c/o Ralph Pugh Co., 532 Howard St. Johns-Manville Co., H. W., Second and Howard Sts. Knight & Thomas, c/o E. T. Bond, 311 California St. 368 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION Missouri Lamp and Mfg. Co., c/o Goodyear Kubber Co., 587 Market St. Northern Fire Apparatus Co., c/o P. Brant, 67 Main St. Pittsburgh Lamp, Brass and Glass Co., c/o A. A. Otte, 618 Mission St. Pyrene Mfg. Co., 76 First St. Standard Extinguisher Co., c/o Gorham Fire Ex. Co., 127 Mission St. Stempel Fire Extinguisher Mfg. Co., c/o P. Brant, 67 Main St. LITERATURE 1. Fire Prevention and Fire Fighting on the Farm. H. E. Tolley and A. P. Yerkes. Farmers' Bulletin 904, U. S. Dept. of Agriculture, January, 1918. 2. Suggestions for Fire Prevention and Protection as Applied to Grain Separators. Washington Surveying and Rating Bureau, Seattle, Wash., July, 1917. 3. Dust Explosions and Fires in Grain Separators in the Pacific Northwest. U. S. Dept. of Agriculture Bulletin no. 379. 4. Care and Repair of Farm Implements. E. B. McCormick and L. L. Beebe. Farmers' Bulletin 947. Numbers 1, 3 and 4 may be obtained free of charge from the Editor and Chief of the Division of Publications, Washington, D. C. Number 2 may be secured from the bureau above mentioned. Address P. O. Box 1818, Seattle, Wash.