Fire Protection And Insurance
( Originally Published 1911 )
Fire losses.-The annual loss from fire in the United States amounts to nearly $3 per capita, and shows but little diminution in the past fifty years. The losses since 1878 are as follows:
Years Aggregate Property Loss
These figures demonstrate the necessity for fire protection. The United States presents a fire-protection problem unequaled in history. It may be safely estimated that one-half of the fire losses in the whole world occur in the United States, and it is probably equally true that one-half of the amount paid in the world for fire insurance is paid in the United States. On the continent of Europe and in England the losses by fire do not amount to more than a tenth of those in the United States. This is due principally to improved building construction, to better enforcement of fire laws, and, apparently, to greater respect for law in general.
Prevention of fires.—The foregoing facts among others led to a study of the causes of fires, and then to a study of the means of prevention. It is said that 90 per cent of the fires in a cotton mill start in the picker-room. The fact that statistics enable us to locate 90 per cent of such fires enables us to determine where prevention should first be applied. The work of the fire-protection or "insurance" engineer deals with this problem of fire-protection worked out through appliances for preventing or extinguishing fires. The field of his labor is shown in the following incomplete list
a. Fire doors and shutters.
Fire-doors.—The necessity of confining the area subject to a fire to small units is understood. There is a difference of opinion as to how large that area should be. In some cases 1,000 square feet constitute the unit, charges being made for additional area; in others 2,500 square feet, while in a fireproof building 5,000 feet. The conception of a business in a building 25x100, with an area of 2,500, grown to such extent as to necessitate the use of the building adjoining, will make clear the origin of the fire-door. A merchant taking the second building may have an opening on each floor cut into the adjoining building. Thus in-stead of 2,500 square feet subject to fire on each floor there are, by open communication with the adjoining building, twice that area. In the very beginning of this practice it was recognized to be dangerous and means were sought whereby these openings might be sufficiently protected to prevent fire passing from one building to another. Iron doors were the first protection adopted after the wooden door was found to be of little use.
Features of door-openings.— (1) Openings in the wall should not exceed eighty square feet and should be as few as possible.
(2) There should be one door on each side of the wall, preferably both sliding, though one may be swinging.
(3) The size and shape of the door and the sills and lintels are covered by the specifications.
(4) The wood in the door, or the core, should be of well-seasoned white pine or of a similar non-resisting wood. There should be three thicknesses of board, the outer layers being vertical and the inner horizontal. They are-securely fastened together with wrought-iron clinch-nails, leaving the surface smooth.
(5) The fire-resisting value of the tin-covered wooden door depends upon preventing access of oxygen to the wood. To obtain this result the covering must be applied so that the joints between the tin remain intact, provision being made for the escape of the gas from the wood core.
Although the foregoing covers the more important features of the standard door, the hardware, the hanging, etc., should also be carefully noted.
The standard doors which operate automatically are held open by a "fusible link." This link, melting under the action of heat at about 160 degrees, releases the door, which closes and covers the opening in the wall.
Standard fire shutters.—The standard fire shut-ter on the outside of the building protects property from exposure and is similar in form to the standard fire-door. The objection to shutters is that when they are closed at night the interior of the building cannot be seen.
Wired glass.—This kind of glass apparently was first used in England at an election. It was desirable to look into the ballot boxes while the votes were being cast, at the same time having the boxes closed. A wire mesh was placed between two panes of glass, thus furnishing an opportunity to see within the box but keeping the ballots safe. An accident disclosed that wired glass was a fire retardent. Ordinary glass melts at from 800 to 1,000 degrees Fahrenheit, but by embedding a wire mesh into it the melting point is raised to from 1,800 to 2,200 degrees.
There is slight advantage in wired glass if a wooden frame is used for the sash. Metal-covered wooden sashes came into use, and later a hollow metal frame was adopted. The window is occasionally double glazed; that is, has two panes of wired glass with an air space between them. The general opinion is that within thirty feet the double wired glass in metal frame is as good as the standard shutter, while beyond thirty feet a single pane of wired glass in metal frame is as good as the standard shutter. These are general working rules, however, and are not to be implicitly relied upon in every instance.
Waterworks.—The pressure for distributing water through a system of pipes may be obtained in the following ways: by gravity only; or by first pumping the water to an elevated reservoir, whence it flows into the pipe system by gravity; or by pumping the water to an elevated tank or standpipe; or from pumps that force the water directly into the distributing pipes. The pipe system everywhere is practically the same. For fire extinguishing purposes the gravity system, especially if it receives and distributes in duplicate conduit, is the best and the most reliable. It has less apparatus to get out of order than the other systems.
Use of hydrants.—When the pressure in the mains is sufficient, fire streams may be taken directly from the hydrants. If the pressure is low, however, steam fire engines are necessary. High pressure is of great value, especially in small cities and towns, as it eliminates the necessity of fire engines, though a few of these should be kept in reserve for emergencies.
To be available for hydrant fire pressure the pressure in the mains should produce at hydrants, when properly spaced, a 240 or 250-gallon capacity in business districts and a 175 to 200-gallon capacity in the residential localities. With high pressure, hydrants do not need to be as closely set together as with low. With close hydrant spacing a sixty-pound pressure for the residence district and a seventy-pound pressure for the business district are not uncommon, though for effective streams an 80-pound and a 100-pound pressure are desirable. In small towns supplied by the gravity system the sixty to seventy-pound pressure may suffice, as a higher pressure would not be sufficient compensation for the expense of producing it.
Arrangement of pipes.-The best arrangement of pipes for distributing water is one in which the mains run at right angles to one another and connect at every street intersection. By this "gridiron system" the mains are fed at both ends. The amount of water needed in any locality regulates the size of the mains and cross pipes. Small cities and outlying districts of large ones require six-inch cross mains with eight, ten or twelve-inch pipes at intervals of from four to six blocks. Larger places or compactly built districts require eight-inch cross mains with an occasional twelve to sixteen-inch main, or six-inch pipes running lengthwise and eight-inch pipes crosswise. Unusually large areas may re-quire larger feeders, such as twenty-four, thirty-six or even forty-eight-inch pipes. As the safety and comfort of a city depends upon its water supply, the efficiency of the pumping station should be assured. It should be of fireproof construction and removed from such hazards as factories, electric light stations, etc.
Fire boats.—Fire boats are of valuable aid in cities located near bodies of water. These boats are generally used for fighting fires along the rivers, although they may supply water to special pipe lines running from the water front to other parts of the city. These boats usually have very powerful pumps, equal in efficiency to from ten to thirty-five or more fire engines.
Public fire department.—With the public fire department the fire-protection engineer has little to do. The department grew out of the volunteer system, continued in force in the United States until the early sixties, but now since the introduction of the steam engine rapidly declining. It is only recently that the necessity has arisen for a fire-protection engineer to take charge of the public fire department, but several now specialize in that branch.
Private fire department.—The necessity for a private fire department is based on the fact that when a fire starts there should be a trained organization always ready to act, not waiting until a fire occurs and then depending upon chance or the inspiration of the moment.
Standpipe equipments.—In general all city or mill buildings over three stories high and all open or inclosed structures that cover large areas irrespective of their height, require a standpipe equipment for their proper protection against fire. If the buildings are so near one another that the use of hose from the roofs may be advantageous, the standpipes may be extended to supply roof hydrants. The special function of the standpipe is to carry water for hose streams to upper floors, thus eliminating the difficult handling of hose and ladders that causes so much delay. Minor details must be determined by the local fire department and the local insurance authorities with reference to each particular building and the water supply available.
Automatic sprinklers.—It is an adage among insurance workers that any fire could readily be put out if at the time of its origin someone were there to throw a cup of water upon it. This adage emphasizes the time element. Efficient fire protection depends upon being ready to stop the small fires before they become powerful and destructive. Of the many means to effect this immediate extinction the automatic sprinkler is perhaps the most successful. It has been described by an authority as follows:
The sprinkler head itself consists of a casting with a one-half inch orifice, designed to screw into the pipe fitting, the orifice being closed by a cap held in place by strut or levers composed of pieces of metal held together with fusible solder. There is also a deflector or splash plate against which the water impinges, and each sprinkler is designed to protect the floor area of from 80 to 100 square feet. The piping is attached generally to the ceiling, the sprinklers being spaced eight to ten feet apart. It is evident that for the sprinkler to be effective there must be a water supply of sufficient pressure and volume, while for a standard equipment two water supplies are required.
History of automatic sprinklers.—The earliest reference to any device considered as coming under the automatic sprinkler class was in a patent granted in 1723 for a fire-extinguishing apparatus consisting of a cask filled with a fire-extinguishing liquid to be released and set into action by means of a small can of gun-powder connected to a system of fuses. There is a record in 1727 of a fire extinguished by this device.
In 1806 John Carey invented an apparatus for automatically extinguishing fires, making use of perforated sprinklers connected with piping. In 1809 Sir William Congreve secured a patent covering an automatic fire-extinguishing system. It appears to have been similar to Carey's, but in 1812 he took out a second patent in which a fusible substance instead of a cotton cord was to be used for releasing the water. This appears to be the earliest reference to the use of a solid substance melting at low temperature and setting the sprinklers in operation. Nothing practical came of these early attempts. In 1864 Major A. Stewart Harrison, who was connected with the first London Engineer Volunteers, in-vented what seems to have been the first automatic sprinkler constructed on modern lines, yet it is now conceded that the first commercially successful sprinkler was invented by Henry S. Parmelee, of New Haven, the patent thereof being dated August 11, 1874. In 1875, 2,500 of these sprinkler heads were installed in the mills at Fall River. The Parmelee sprinkler used a fusible solder that melted at 160 degrees. For ten years, however, after the Parmelee sprinkler was in-vented, but little progress had been made in introducing the device. In 1881 Frederick Grinnell, of Providence, invented the sprinkler that still bears his name. To Grinnell more than any one else is due the commercial extension of automatic sprinkler protection. Subsequently other persons invented and placed on the market successful sprinkler heads. To-day there are several on the approved list.
While to Grinnell much credit is due for the improvement in sprinkler protection, yet equal praise is due for its advocacy and adoption to the mutual fire insurance companies of New England. They were the first companies to test the system and to instal it in the most hazardous portion of the properties they insured, later extending it to all. In due time the stock companies discovered that they were losing business to the mutuals, and they, too, adopted the sprinkler device.
Value of sprinkler protection.—The results of sprinkler protection are well stated in a letter written by President R. W. Toppin, of the Arkwright Mutual Insurance Company of Boston, to the Automatic Sprinkler bulletin. The letter states briefly and concisely the loss from fire before and after the introduction of the sprinkler:
The first automatic sprinklers put into mills insured by this company were installed about 1875. During the fifteen years of the business of this company prior to 1875, in round figures, the
Insurance written aggregated $118,300,000.00
During the first years of automatic sprinkler protection the progress of installation was somewhat slow, though it continued steadily. In the second fifteen-year period, from 1875 to 1890, the
Insurance written aggregated $509,000,000.00
or, in other words,
Insurance written increased 33.8%
As the value of automatic sprinklers for the extinguishing of fires became more and more evident by their remarkable success in reducing fire loss the Mutual Companies began to require their installation throughout all parts of manufacturing plants where formerly they were required only in rooms where the more hazardous processes were carried on or which contained large values, until to-day practically every part of our manufacturing risks is protected by automatic sprinklers, and they have been extended to nearly all storage buildings insured by us. The result of this has been a remarkably low loss ratio, viz.:
During the ten years ending Dec. 31, 1907, the Insurance written aggregated ...$1,552,000,000.00 The losses were 774,500.00 Average yearly loss per $100 . . . ..05.
Compared with the first fifteen years of our business with no automatic sprinklers the Insurance written increased over 1200% The loss ratio reduced 79%
Taking all the business of the Mutual Companies represented in the Senior Conference during the year 1907 the
Insurance aggregated $1,816,000,000.00
It should be remembered that these results were obtained upon manufacturing risks, the hazards of which are generally considered more than the average.
The figures presented speak forcefully for the value of fire protection, of which automatic sprinklers form a very considerable part.
Additional testimony is furnished by reports of the National Fire Protection Association, which has kept a close record of sprinkler fires during the thirteen years of its existence. Its records show 8,942 fires in sprinklered risks where the sprinklers operated. The operation of the sprinklers was unsatisfactory in only 843 cases, or 5 per cent. The causes of failure were generally due to closed gate valves, defective equipment, defective water supply, exposure or conflagration fires, faulty building construction, and serious obstructions to the distribution of water. The records also show that in 30 per cent of the fires only one sprinkler opened, thus showing that the cup of water does a large part of the work. In 55 per cent of fires three or less than three sprinklers opened, and twenty-five or less in 90 per cent. It is a rule that where more than twenty-five sprinklers open, it is due to some condition not found in the ordinary risk.
Spread of sprinkler protection.—The spread of sprinkler protection is shown by the fact that one-third of the property insured against fire in New England comes under this system, while in New York City more than $300,000,000 worth is thus protected. The total amount throughout the United States is not now avail-able in figures, but it is believed that within ten years there will not be a single manufacturing or mercantile risk of much value unprotected by automatic sprinklers. The reduction in the rate of insurance will be enough to warrant this, while the inability to obtain insurance without such protection will hasten it.
The fusible metal or solder used in sprinklers is adjusted to different temperatures according to the character of occupancy of the building to .be protected. The ordinary sprinkler head has a melting point of about 160° Fahrenheit, but heads melting at as high as 212° to 400° Fahrenheit are used in dry rooms, boiler rooms, and other places of high temperature.
Requisites of sprinkler protection.—The requisites for obtaining the best automatic sprinkler protection are :
The building should be open in construction, the sprinklers being so located that distribution may cover all points on the premises. This means that sprinklers should be installed in basements and lofts, under stairs, inside elevator wells, in belt, cable, pipe, gear and pulley boxes, inside small inclosures, such as drying and heating boxes, tenter and dry-room inclosures, chutes, conveyor trunks, cupboards, and in chests unless they have tops entirely open and so located that sprinklers can properly spray therein. Sprinklers should not be omitted in any room merely because it is damp, wet, or of fireproof construction. Special instructions should be obtained as to placing sprinklers inside show windows, boxed machines, metal air ducts, ventilators, concealed spaces, under large shelves, benches, tables, overhead storage racks, over dynamos and switchboards, plat-forms and similar water-sheds.
The piping should be of sufficient capacity, as a system is of little value unless the riser pipe and distributing mains are of sufficient size to supply the sprinkler heads.
Steam, rotary and electric fire pumps should be installed in accordance with the rules of the National Board of Fire Underwriters. It is required that with five pounds pressure maintained at the sprinklers each head shall discharge approximately twelve gallons per minute. The sprinklers should, therefore, be made with an unobstructed outlet of sufficient size and suitable form to accomplish this result. Siamese sidewalk connections should be provided for the use of the fire department for direct attachment of fire engines to risers.
The circulation of water in sprinkler pipes is objectionable owing to increased corrosion and deposit of sediment. For this reason the pipes of a sprinkler system should not be used for domestic or other than fire service. Hand hose for fire purpose only may be attached to sprinkler pipes within a room under the following restrictions : Pipe nipple and hose valve are to be one inch; hose to be one and one-fourth inches; nozzle to be not longer than one-half inch. Hose is not to be connected to sprinkler pipe smaller than two and one-half inches and not to be attached to a day pipe system.
Automatic alarm.—In order to detect the presence of fire or of a leak in a sprinkler system every equipment should have an automatic alarm device or possess a watchman service. Sprinkler heads have been known to open and permit water to flow from Saturday night to Monday morning, there having been no alarm device to indicate the flow.
Dry pipe.—A dry pipe system should be used only where a wet pipe system is impracticable; as, in buildings or portions of buildings having no heating facilities. The use of such a system is, however, far preferable to shutting off entirely the water supply during cold weather. To keep the water out of the pipes a valve, called a dry valve, is employed. The sprinkler pipes are filled with air under pressure and should so remain throughout the year. When a sprinkler head opens the air escapes, the reduction in air pressure al-lowing the water pressure to open the dry valve automatically. The water then enters the sprinkler system and is discharged through the open sprinkler heads.
Open sprinklers.—Open sprinklers are metal orifices placed outside a building just over the windows along the cornice on the side wall or along the ridge pole. Their purpose is to protect from exposure- fire and to prevent flames from passing through the windows from floor to floor. The sprinklers consist of an orifice with a horizontal level-shaped disc for deflecting the water into a sheet of spray. This spray can be made to form a solid water curtain along the side of a building.
The failure of the sprinkler system is most frequently due to a valve being closed at the critical moment or to deficient water supply; therefore, in the interest of the assured, the system should be periodically inspected by a competent person.
Chemical fire extinguishers.—The use of other substances than water or in combination with water as a fire extinguisher attracted the attention of inventors from an early period. Chemical fire extinguishers, both hand and wheel, found in public and private establishments, and chemical extinguishers used by fire departments, are devices for the use of chemicals combined with water. The chemical itself does not add to the extinguishing quality of the water. Its function is to generate a gas to drive the water either to a greater distance or with greater force.
Hand extinguishers.—There are now many chemical devices for extinguishing fire, but with the exception of those operated by carbonic acid gas, they have proved most unsatisfactory under actual test.
The carbonic acid gas extinguisher consists of a cylindrical copper tank with a small hose attached. It is filled with a solution of bicarbonate of soda, while at the top of the tank, kept separately, is a glass container of sulphuric acid, closed with a loose lead stopper. In operation the extinguisher is inverted, the two fluids thus mingling and generating carbonic acid gas. This produces considerable pressure and expels through the hose the water charged with the gas, which is a non-supporter of combustion.
With all the good points of extinguishers it must still be said that they have not the simplicity and dependableness of pails of water; consequently they should not entirely replace fire pails. Extinguishers may replace one-half the number of fire pails on a floor, on the basis of an approved three-gallon extinguisher for six pails, but no more. They should be set and located very much as fire pails. Extinguishers should be examined twice a year, tested and recharged, as in this manner valuable knowledge may be obtained by employes as to the operation of the device.
Wheeled engines are similar to hand fire extinguishers in make-up and operation, but instead of three gallons they usually contain forty. They are mounted on wheels to permit easy movement. Each engine has fifty feet of hose and throws a stream from twenty-five to eighty-five feet beyond the nozzle. Such engines are especially valuable for private fire departments in stores, warehouses, hotels and factories, or about large country residences.
Fire pails.—The oldest vessel used for the purpose of extinguishing fires is the fire pail or bucket. Long before fire insurance was devised the fire pail was the only generally approved instrument for putting out fire. This means that pails or buckets filled with water were set aside to be used for this purpose. The factory mutuals state that one-half of their fires are extinguished by a pail of water. If used at the proper moment, a fire pail is of greater service than the entire fire department a few minutes later. It is cheap; its purpose is understood by all; and it may readily be kept in condition for use. Everyone can use a pail of water; while the average person, especially when excited, does not understand a patent fire extinguisher or may not know how to turn a standpipe valve and use the hose. The value of the fire pail is well recognized by all insurance companies, by all fire departments, and by others interested in the safety of life and property.
Since the general purpose of all these various appliances is to put out fires and that as quickly as possible, it is apparent that whatever extinguishers are used should be understood by the person responsible for their use and that the appliances themselves be kept in good condition. A fire pail is of little use unless filled and kept within reach. For this reason the pails are usually painted red and marked with black letters "For Fire Only." Other regulations specify the number of pails required, their location, and capacity; and when such regulations are met, the insurance companies as a rule grant liberal reduction in rates.
People with the best of intentions often instal. costly fire protection equipment which through neglect is found altogether useless when a fire breaks out. Knowledge of this tendency to neglect things has caused insurance companies to draw up certain rules and regulations, the following of which are examples:
Signaling systems.—In addition to the means at hand for putting out fire it is necessary that someone should be present to use them. This is not always possible, especially when plants are not in operation, or business is closed for the night, or on Sundays or holidays. To overcome this difficulty systems of signaling have been devised, all of which may be embraced under the general term of "Signaling systems."
Centuries ago, it was the custom to have towers in each city and village, on which watchmen were stationed throughout the night to raise an alarm in case of fire. This system is still prevalent in certain foreign countries, while on the Island of Nantucket it was not discontinued until 1907.
Electric signal.—The system for the electrical transmission of an alarm of fire was invented about twenty years after the first telegraph was erected between Baltimore and Washington, Up to that time notice had been transmitted by the lookout system, and as cities grew larger a division into districts took place so that an alarm for one would not arouse the whole city.
The automatic fire alarm operates by the action of heat, notifying the fire department in this way not merely of the presence of fire but the exact location as well, thus reducing to a minimum the time for reaching it.
Special building signal.—The special building signal runs from a specific building to the fire department headquarters. It operates, however, by hand, not being automatic. To be successful, therefore, there must be someone on the premises to operate it. This feature is recognized by a difference in the insurance rate for a building protected by a watchman during non-business hours.
Automatic sprinkler supervision.—This is a system of fire-signaling connected with sprinkler devices. It is of value in that it operates when the water flows, and to that extent is more efficient than the automatic alarm that operates under the action of heat only. It is evident that unless notice was received, in a system so complicated as the sprinkler, an accident may occur that would turn the water on and without any fire do an immense amount of damage.
Watchmen.—It is difficult to standardize human beings, but with a watchman's service, public or private, efforts have been made to reach as near to standardization as possible. The watchman is a type of workman who will probably never pass away despite all the improvements in mechanical devices that encroach upon his field. Since ordinary prudence ought to forbid leaving buildings and their contents without care or super-vision during nights, Sundays, holidays, or any other non-business period, the employment of watchmen against fire or burglary has been the rule rather than the exception. The fire insurance companies recognize in the rate of a building, the presence or absence of an approved watch service, having adopted this practice after long experience with the discovery and prevention of fire.
Safety receptacles for ashes, etc.—Fires are frequently caused by hot ashes being thrown into wooden boxes or barrels, or into receptacles containing combustible materials. Fires so started during the night or when a place is deserted may gain considerable head-way before discovery. Covered metal ash cans almost entirely eliminate the possibility of such a fire. Cans of good, galvanized iron or steel, reinforced with steel staves and having hoops at the bottom, are recommended for this purpose.
Oily waste.—Spontaneous combustion or ignition is by no means a rare cause of fire. Fibrous, porous, or finely divided materials if soaked with vegetable oil are likely to catch fire. Vegetable oils have great affinity for the oxygen in the air, forming a combination that may generate enough heat to light a fire. For this reason, cotton waste, sawdust, fine shavings, etc., if at all oily, need special attention. Such materials when collected during the day's work should be put into a metal receptacle known as the "self-closing waste can."
Packing bin.—A suitable receptacle should be provided whenever excelsior, straw, hay, cut paper, or other loose packing material is used. Since inflammable material adds to the spread of fire in addition to the danger of spontaneous combustion, or quick ignition by sparks, matches, etc., the necessity of confining such material in a proper inclosure is clearly evident.
General standards are not available for some of these devices. Those furnished in this chapter are the out-growth of experience in one of the largest cities in the country. They cover many points generally found only in building codes, or in office rules, not subject to the notice of the general public.
Necessity for standards.—The more delicate and intricate a piece of mechanism is the more care it re-quires. Even the fire pail, perhaps the simplest device for fire fighting, requires a certain amount of care to be kept in good condition and available for use when wanted. Clearly the better the article at its installation the less care will it require and the more efficient will it be when called upon to do its work. It would be pleasant indeed if fire fighting devices could be installed with a guaranty of doing exactly what is wanted when a fire occurs.
There always was some slight effort to keep an over-sight of fire fighting devices, even in the days when simplest methods were in vogue. Thus the fire pails were required to be of a certain size, to be kept in a certain manner, and to be used for no other purpose. When sprinkler installation began it was found that these equipments—consisting as they did of many feet of pipes with valves, water supply and various other features—required a constant inspection. The sprinkler itself—possibly the most vital part unless it be the water supply—once installed must not be permitted to depend upon a fire to test it out. It must be subjected to a laboratory test before the installation.
National Fire Protection Association.—The National Fire Protection Association, founded in 1896, instituted the plan of devising certain standards for fire fighting devices. The following list illustrates the requirements :
Cast iron mains and their proper construction.
This list is sufficient to show the extension of the business of fire protection. Insurance companies have given no special attention to the invention of fire protecting devices. They confine their efforts to standardizing those already existing which have been approved.
Laboratory testing.—If standards are to be established, it follows as a matter of course that there must be some place for testing the various devices. This is now done at the underwriters' laboratory in Chicago, established several years ago and now under the control of the National Board of Fire Underwriters. It under-takes to test the products of any manufacturer and takes up problems submitted by the underwriters. The standards recommended are published as the standards of the National Board of Fire Underwriters, whose headquarters are in New York City. In England the work is done by the British Fire Prevention Committee, which maintains a laboratory or testing station. Its work corresponds somewhat to that done in the United States, although it does not have, perhaps, as in this country, the full official sanction of the insurance companies. The mutual fire insurance companies also maintain a laboratory in Boston for the testing and carrying forward of the work in which they are interested.
96. Field inspections.—The work of testing is taking the form that will probably characterize it in the future. It is evident that a manufacturer of fire doors would find it inconvenient to ship every fire door to Chicago to be tested. To overcome this difficulty, an inspector rep-resenting the laboratory visits the manufacturing plant, examines the work and places thereon the seal of approval. This is called "field inspection." The inspection at first covered only wires used for electrical purposes, but is rapidly extending and now includes wired glass windows, standard fire doors and shutters, and many other devices.
Place of the engineer.—The business of fire insurance is gradually becoming scientific, if that term may be used in a somewhat modest manner. More and more the fire engineer is coming to have a fixed place ; and as the nation awakes to the fact that it is of more importance to prevent fire than to put it out, so will the demand for his work increase.
An additional fact which has made the work of the engineer necessary is the need for cooperation among the insurance companies. If each one hundred and sixty companies in the field were to adopt its own standard and rules for the installation and making of fire fighting devices, it is clear that there would be no standard which the insured would adopt or even seriously consider. The fire insurance field is largely co-operative. A single, company is able to insure only a part of a plant; thus the insured must have the policies of several companies to be fully protected. This being the case it is desirable on the part of the companies to unite on at least the fire engineering branch of the business, a branch in which there is the least doubt as to the success of co-operation.