PAPER PRESENTED BY FREDERICK GRINNELL, Esq.,

PROVIDENCE, R.I.

The paper which I am permitted to read to you, relating to fire-extinguishing apparatus, has been prepared at the suggestion of Mr. Edward Atkinson, whose present responsible position as President of the Boston Manufacturers' Mutual Insurance Company demands of him in your interest to make thorough investigation as to the efficiency of existing appliances, correct their defects, and bring to your attention such improvements as he may judge worthy of introduction. I do not lay claim, gentlemen, to any special ability to present this subject to you: on the contrary, such practical information as my business experience has afforded me, and the special thought bestowed upon it during the limited time I have now had at my disposal, has led me to feel that it is impossible for me to do the subject justice. I have been forcibly impressed with the fact that the whole business of extinguishing fire is in a crude and unsatisfactory condition.

City fire departments supplied with magnificent steam fire engines, the most effective machine that human ingenuity has been able to devise for the purpose,― notified of the exact location of the fire by the electric alarm, and an organization which results in the utmost promptness in reaching and attacking it, seldom accomplish much more than prevent its spread to adjacent buildings.

This is especially true in case of fire in the lofty stores and warehouses of our great cities.

Buildings, fire-proof so called, filled with costly merchandise, are swept away by the devouring flames; their very fire-proof qualities baffling the efforts of the firemen by preventing their entrance, or resisting their attempts to cut through floors or partitions to get water on the fire:

All becomes a matter of chance and uncertainty, while every now and then we are appalled by accounts of disastrous conflagrations which sweep away whole towns, or destroy large portions of our great cities.

Vast expenditures may place at our disposal abundance of water in the street-mains of our city water-works, but we are not able to use it with sufficient promptness and effect.

In our factories the condition of things is little better, or at best far from satisfactory. The appliances required under the mutual system of insurance have unquestionably been of great value in saving property; great numbers of fires have been extinguished in their early stages, and especially by the help during working hours.

If, however, there is a slight delay in doing this, or a fire takes in the night and is not quickly discovered and subdued, it defies the best-directed efforts; and a total destruction of the property, or at best a serious loss, is the result.

The question, then, for us to consider is, whether it is possible for us to make any improvements in our present method of extinguishing fire.

It is certainly a very important question, measured as it is by the annual loss of hundreds of thousands of dollars to our manufacturing interests, and by millions to the general interests of the country. After first considering the extinguishing appliances now in general use in your factories, I shall ask your attention to the matter of applying water to fire automatically by the effect of its own heat. Many here present, who have given this matter attention, are fully convinced that the principle is a correct one, and believe that an appliance which will successfully carry it out would prove of great value.

Unquestionably there is a deplorable need of something; there is a "missing link," so to speak, in this business of extinguishing fire.

HYDRANTS.

It is not necessary to occupy much time in the consideration. of hydrants, as their arrangement and use are familiar to all. A suitable number located outside the mill at a distance of from fifty to seventy-five feet apart, and about the same distance from the mill, are considered indispensable to protect the basement and lower story when these rooms are not supplied with sprinklers.. "Stand-pipes" in the tower or inside such mills as have no towers, with hydrants and hose attached on each story ready for immediate use, have been found serviceable, and are still adhered to. Stand-pipes outside, with hydrants on the balconies or fireescapes, have proved of little practical value, and, since the general introduction of sprinklers in the upper stories, have been or might better be discarded. At a fire at the American Linen

Mill in Fall River, where there were no sprinklers, these outside stand-pipes no doubt performed excellent service. They were so placed that the hydrant-nozzles pointed into the windows; the water was turned on to the fourth floor, where the fire originated, and the stories below were saved. It should be borne in mind, however, that such a proceeding would in most cases prove very disastrous: a few such open nozzles would render the sprinklers in the stories above useless by drawing the water away from them, and impair of course, to a great extent, the efficiency of the hydrants in the mill-yard.

The question of the amount of water discharged through lines of hose of given size and length, through nozzles of given size and shape, under a given pressure at the hydrants, is a very important one. When a fire-pump is to be procured for a mill, and a system of pipe laid in the yard to connect it with hydrants, or the system of pipe and hydrants are to be supplied from a distant reservoir through a main pipe leading to the mill-yard, it is far better to know the amount of water necessary to supply a given number of hydrants with a certain degree of efficiency, and provide for it, than to guess at the whole matter as has been too often done, and make a useless expenditure for practically worthless appliances. It is especially true that exact calculations are demanded in supplying water from reservoirs. If a way could be discovered to make a large pipe cost less than a small one, it would unquestionably be safe enough to leave the size to be guessed at; nothing, I think, but the cost of digging the trench would in most cases limit their size, in the present depressed condition of our manufacturing industries.

As it is, the size is very generally far from adequate, and a six-inch pipe is often bought and laid without the slightest consideration of the very pertinent fact that an eight-inch pipe, costing about one-third more money, will convey a given quantity of water per minute with something less than one-fourth the loss of head by friction.

The fact so seldom known or thought of, that the loss of head due to friction varies as the two-and-a-half power of the velocity of the water in the pipe, is one of the few things that may disturb the guessing even of a native-born Yankee. Very extensive experiments have recently been made by Mr. Edmund B. Weston, an assistant engineer of the Providence water-works, to determine the quantity of water which will be discharged

through hose and hose-pipes; and a very valuable formula has been deduced from these experiments, by which the quantity of water which will be discharged through a given length of hose, with various-sized pipe-nozzles, may be determined by observing the pressure at the hydrant. The height and distance to which the streams were thrown were also carefully noted in the experiments referred to.

An interesting fact was noticed in reference to the loss by friction in plain linen or rubber-lined hose, which was that the difference was of no practical account in its effect upon the amount of water discharged or the efficiency of the streams. This results from the great difference in the velocity of the water in the hose and at the nozzle; a slight difference in the diameter of the hose would vary the result more than the nature of its internal surface.

SPRINKLERS.

Let us now pass to the consideration of sprinklers, an appliance which has been largely introduced into your factories during the past few years.

They consist, as you are all aware, of a system of perforated pipe placed near the ceiling of the room, and connected with a supply-pipe through which water may be introduced and forced out of the perforations in small jets.

The first introduction of sprinklers in mills, no doubt, occurred in picker-rooms; and their efficiency as a means of extinguishing fire often tested and well established before they were introduced into other portions of the building where fires were less frequent. The first general introduction into carding and spinning rooms took place in the mills at Lowell in 1852, under the supervision of Mr. James B. Francis and in the manner described by him in a very interesting paper written for the Journal of the Franklin Institute for April, 1865. Under his direction the work was carefully and skilfully planned with a view to making the protection as perfect as possible with the water supply which was then available.

The advantages of an effective system of sprinklers over hydrants and hose scarcely admits of a doubt. The upper stories of a five or six story mill are practically beyond the reach of hydrants in the yard, and the limited number of hy. drants in the rooms can only be made effective when used with

the utmost promptness in the early stages of a fire. In fact, much more has usually been accomplished with a plentiful supply of buckets kept filled with water.

The fire spreads with such rapidity when not subdued with water from the buckets as to get beyond control with a line or two of hose, and it is then that sprinklers may perform efficient service. They may be made to discharge a large amount of water over the entire area or beyond the limits of the fire; and by wetting the ceiling, the contents of the room, and the floor, all at the same time, a fire of very considerable proportions may be extinguished.

Let us next consider what constitutes an efficient system of sprinklers capable of bringing about the very satisfactory result we have above pictured. We must consider the arrangement of pipe, the quantity of water that should be delivered over each square foot of floor which is to be protected, the total quantity of water required for one or more stories of an averagesize mill, and the means or appliances necessary to furnish it.

Mr. William B. Whiting, Secretary of the Boston Manufacturers' Mutual Insurance Company, inaugurated the plan of running the lines of perforated pipe lengthwise the building, directly under the main floor beams, with three lines of orifices in them; one line directly on top of the pipe, and a line on each side at an angle of sixty degrees from the centre line, or, as it has been often expressed, in the position of the ten, twelve, and two o'clock figures on the face of a watch. It being decided that pipe with three rows of orifices would be used, I made extensive experiments to ascertain what diameter the orifices should be, and the number in each lineal foot of pipe, to discharge water at an acceptable rate, and also to determine the proper size for the lines of perforated pipe in order to effect a satisfactorily uniform discharge the entire length of the lines.

As one of many results, it was found that if water was supplied to a line of perforated pipe fifty-five feet long, under a head of forty feet, with three orifices in each lineal foot of pipe, orifices one-fourteenth of an inch in diameter would give an average discharge of thirty-three thousandths of a cubic foot per minute each, which would be, say, a tenth of a cubic foot of water discharged from each lineal foot of pipe.

This experimental line consisted of twenty-eight feet of oneinch, and twenty-seven feet of three-quarter-inch pipe. In