Chapter 4

In London the Building Act forbids all such proceedings, but the District Surveyors do not seem to have sufficient power, or be able to pay sufficient attention to such matters, as they are constantly met with at fires. A very flagrant case of laying a hearth on timber was lately exposed by a fire in the City. Due notice was given of the circumstance, but no farther attention was paid to the matter than to make the proprietor construct the floor properly, although the Act gave power to fine for such neglect. The omission is to be regretted, as there could not have been a better case for warning others; it occurred in a very large establishment, and the work was done by one of the first builders in the City. Had this fire taken place in the night and gained some head, it would have been very difficult to have ascertained the cause. As the premises were situated, a serious loss of life might have occurred, the apartment in which the fire originated being the only means of retreat which ten or twelve female servants had from their bedrooms.

The Metropolitan Building Acts, up to about the year 1825, by insisting upon party-walls and other precautions, were invaluable for the prevention of the spread of fires. By them no warehouse was permitted to exceed a certain area. From the year 1842, the area has been exchanged for a specified number of cubic feet. But since 1825, a class of buildings has arisen of which there are now considerable numbers in the City, called Manchester or piece goods warehouses, which somehow have been exempted from the law restricting the extent of warehouses, on the plea that they are _not_ warehouses, because "bulk is broken" in them, although it is thoroughly understood that the legislature intended by the Act to restrict the amassing such a quantity of goods under one roof as would be dangerous to the neighbourhood.

Manchester and piece goods warehouses have for some time past been built in London of unlimited size, sometimes equal to twenty average houses. This is pretty nearly the same as if that number of houses were built without party-walls, only that it is much worse, for the whole mass generally communicates by well holes and open staircases, and thus takes fire with great rapidity, and, from the quantity of fresh air within the building, the fire makes much greater progress before it is discovered. By this means the risk of fire in the City has been greatly increased, not only to such warehouses themselves, but to the surrounding neighbourhood, for it is impossible to say how far fires of such magnitude may extend their ravages under untoward circumstances, there being at present no preventive power in London capable of controlling them. To provide such a power would be a very costly business.

Such buildings are also against the generally received rule, that a man may burn himself and his own property, but he shall not unduly risk the lives and property of his neighbours.

The new Building Act is likely to repress, to a certain extent, this great evil, unless its meaning be subverted by some such subterfuge as destroyed the efficiency of the last one. But what is to be done with those which are already built? It may seem tedious to dwell so much on this subject, but it appears to be a risk which is not generally much thought of, though it is of the most vital importance to the safety of London. It is very desirable that the metropolis should take warning by the experience of Liverpool, without going through the fiery ordeal which the latter city did.

From 1838 to 1843, 776,762_l._ were lost in Liverpool by fire, almost entirely in the warehouse risks. The consequence was, that the mercantile rates of insurance gradually rose from about 8_s._ per cent. to 30_s._, 40_s._, and, it is said, in some cases, to 45_s._ per cent. Such premiums could not be paid on wholesale transactions, therefore the Liverpool people themselves obtained an Act of Parliament, 6 and 7 Vic., cap. 109, by which the size and height of warehouses were restricted, party walls were made imperative, and warehouses were not allowed to be erected within thirty-six feet of any other warehouse, unless the whole of the doors and window-shutters were made of _wrought iron_, with many similar restrictions. This Act applied to warehouses already built as well as to those to be built, and any tenant was at liberty, after notice to his landlord, to alter his warehouse according to the Act, and to stop his rent till the expense was paid. Another Act, 6 and 7 Vic., cap. 75, was also obtained, for bringing water into Liverpool for the purpose of extinguishing fires and watering the streets _only_. It is supposed that the works directed, or permitted, by these two Acts, cost the people of Liverpool from 200,000_l._ to 300,000_l._ Shortly after these alterations had been made, the mercantile premiums again fell to about 8_s._ per cent.

There is another very common cause of fire, which seems to come under the head of construction--viz., covering up a fireplace when not in use with wood or paper and canvas, &c. The soot falls into the fireplace, either from the flue itself, or from an adjoining one which communicates with it. A neighbouring chimney takes fire; a spark falls down the blocked-up flue, sets fire to the soot in the fireplace, which smoulders till the covering is burned through, and thus sets fire to the premises.

In theatres, that part of the house which includes the stage and scenery should be carefully divided from that where the spectators assemble by a solid wall carried up to, and through the roof. The opening in this wall for the stage should be arched over, and the other communications secured with iron doors, which would be kept shut while the audience was in the house. By this plan, there would be abundance of time for the spectators to retire, before fire could reach that part of the theatre which they occupy.

_The danger from furnaces_ or close fires, whether for heating, cooking, or manufacturing purposes, is very great, and no flue should be permitted to be so used, unless it is prepared for the purpose. The reason is, that in a close fire the whole of the draught must pass through the fire. It thus becomes so heated that, unless the flue is properly built, it is dangerous throughout its whole course. In one instance of a heating furnace, the heat in the flue was found to be 300 deg., at a distance of from forty to fifty feet from the fire. In open fireplaces, the quantity of cold air carried up with the draught keeps the flue at a moderate heat, from the fire upwards, and, unless the flue is allowed to become foul, and take fire, this is the safest possible mode of heating.

Heating by hot air, steam, and hot water are objectionable. First, because there must be a furnace and furnace flue, and the flue used is generally that built for an open fire only; and second, the pipes are carried in every direction, to be as much out of sight as possible. By this means they are constantly liable to produce spontaneous ignition, for there appears to be some chemical action between heated iron and timber, by which fire is generated at a much lower temperature than is necessary to ignite timber under ordinary circumstances. No satisfactory explanation of this fact has yet been given, but there is abundant proof that such is the case. In heating by hot-water pipes, those hermetically sealed are by far the most dangerous, as the strength of the pipes to resist the pressure is the only limit of the heat to which the water, and of course the pipes, may be raised. In some cases a plug of metal which fuses at 400 deg. is put into the pipes, but the heat to which the plug is exposed will depend very much on where it is placed, as, however great may be the heat of the exit pipe, the return pipe is comparatively cool. But even where the pipes are left open, the heat of the water at the furnace is not necessarily 212 deg.. It is almost needless to say that 212 deg. is the heat of boiling water under the pressure of one atmosphere only; but if the pipes are carried sixty or seventy feet high, the water in the furnace must be under the pressure of nearer three atmospheres than one, and therefore the heat will be proportionately increased. Fires from pipes for heating by hot water have been known to take place within twenty-four hours after first heating, and some after ten years of apparent safety.

The New Metropolitan Building Act prescribes rules for the placing steam, hot-air, and hot-water pipes at a certain distance from timber; but as it must be extremely difficult for the District Surveyors to watch such minute proceedings, it becomes every one who is anxious for safety to see that the District Surveyors have due notice of any operation of this kind.

Another cause of fire which may come under this head is the use of pipes for conveying away the products of combustion. Every one is acquainted with the danger of stove pipes, but all are not perhaps aware that pipes for conveying away the heat and effluvia from gas-burners are also very dangerous when placed near timber. It is not an uncommon practice to convey such pipes between the ceiling and the flooring of the floor above. This is highly dangerous. Gas-burners are also dangerous when placed near a ceiling. A remarkable instance of this took place lately, where a gas-burner set fire to a ceiling 28-1/2 inches from it.

Another evil of furnaces is, that the original fireplace is sometimes not large enough to contain the apparatus, and the party wall is cut into. Perhaps it may be necessary to notice at this point the use of gas, as it is becoming so very general. Gas, if carefully laid on, and properly used, is safer than any other light, so far as actually setting fire to anything goes, but the greater heat given out so dries up any combustibles within its reach, that it prepares them for burning, and when a fire does take place, the destruction is much more rapid than in a building lighted by other means. Gas-stoves, also, from the great heat given out, sometimes cause serious accidents; in one instance, a gas-stove set fire to a beam through a two-and-half inch York landing, well bedded in mortar, although the lights were five or six inches above the stone. This is mentioned to show that gas-stoves require quite as much care as common fires.

_Spontaneous ignition_ is believed to be a very fruitful cause of fires; but, unless the fire is discovered almost at the commencement, it is difficult to ascertain positively that this has been the cause. Spontaneous ignition is generally accelerated by natural or artificial heat. For instance, where substances liable to spontaneous ignition are exposed to the heat of the sun, to furnace flues, heated pipes, or are placed over apartments lighted by gas, the process of ignition proceeds much more rapidly than when in a cooler atmosphere. Sawdust in contact with vegetable oil is very likely to take fire. Cotton, cotton waste, hemp, and most other vegetable substances are alike dangerous. In one case oil and sawdust took fire within sixteen hours; in others, the same materials have lain for years, until some external heat has been applied to them. The greater number of the serious fires which have taken place in railroad stations in and near London have commenced in the paint stores. In a very large fire in an oil warehouse, a quantity of oil was spilt the day before and wiped up, the wipings being thrown aside. This was believed to have been the cause of the fire, but direct proof could not be obtained. Dust-bins also very often cause serious accidents. In one instance, 30,000_l._ to 40,000_l._ were lost, apparently from hot ashes being thrown into a dust-bin.

These accidents may in a great measure be avoided by constant care and attention to cleanliness, and where paints and oils are necessary, by keeping them in some place outside the principal buildings. Dust-bins should, as much as possible, be placed in the open air, and where that cannot be done, they should be emptied once a day. No collection of rubbish or lumber of any sort should be allowed to be made in any building of value.

Mr. Wyatt Papworth, architect, has published some very interesting notes on spontaneous ignition, giving several well-authenticated instances.

_Incendiarism_ may be divided into three sorts--malicious, fraudulent, and monomaniac. Of the former there has been very little in London for many years. The second, however, is rather prevalent. The insurance offices, which are the victims, protect themselves as well as they can, but an inquest on each fire is the true mode of lessening the evil. This is much more the interest of the public than at first seems to be the case. In several instances where the criminals were brought to punishment by Mr. Payne's inquests, people were asleep in the upper parts of the houses set fire to, and in one case there were as many as twelve or fifteen persons. This, however, is seldom stated in the indictment, as, if it is, the punishment is still death by the law, and it is supposed that a conviction is more easily obtained, by the capital charge being waived. Monomania is a rare cause of incendiarism, but still several well-certified cases have occurred in which no possible motive could be given. In one instance a youth of fifteen set fire to his father's premises seven times within a few hours. In another, a young female on a visit set fire to her friend's furniture, &c., ten or eleven times in the course of one or two days. In neither case could anything like disagreement or harshness be elicited, but the reverse. In other instances, it has been strongly suspected that this disease was the cause of repeated fires, but there was no positive proof. In all these cases, known or suspected, the parties were generally from fourteen to twenty years of age.

FIRE-PROOF STRUCTURES.

What is "Fire-proof Construction?" is a question which has given rise to a great deal of discussion, simply, as it appears to me, because the size of the buildings, and the quantity and description of the contents, have not always been taken into account. That which may be perfectly fireproof in a dwelling house, may be the weakest in a large warehouse. Suppose an average-sized dwelling-house 20 x 40 x 50 = 40,000 cubic feet, built with brick partitions, stone or slate stairs, wrought-iron joists filled in with concrete, and the whole well plastered. Such a house will be practically fire-proof, because there is no probability that the furniture and flooring in any one room, would make fire enough to communicate to another. But suppose a warehouse equal to twenty such houses, with floors completely open, supported by cast-iron pillars, and each floor communicating with the others by open staircases and wells; suppose, further, that it is half filled with combustible goods, and perhaps the walls and ceilings lined with timber. Now, if a fire takes place below, the moment it bursts through the upper windows or skylights, the whole place becomes an immense blast furnace; the iron is melted, and in a comparatively short time the building is in ruins, and, it may be, the half of the neighbourhood destroyed. The real fire-proof construction for such buildings is groined brick arches, supported on brick pillars only. This mode of building, however, involves so much expense, and occupies so much space, that it cannot be used with advantage. The next best plan is to build the warehouses in compartments of moderate size, divided by party-walls and double wrought-iron doors, so that if one of these compartments takes fire, there may be a reasonable prospect of confining the fire to that compartment only. Again, cast iron gives way from so many different causes, that it is impossible to calculate when it will give way. The castings may have flaws in them; or they may be too weak for the weight they have to support, being sometimes within 10 per cent., or less, of the breaking weight. The expansion of the girders may thrust out the side walls. For instance, in a warehouse 120 feet x 75 feet x 80 feet, there are three continuous rows of girders on each floor, with butt joints; the expansion in this case may be twelve inches. The tie rods to take the strain of the flat arches must expand and become useless, and the whole of the lateral strain be thrown on the girders and side walls, perhaps weak enough already. Again, throwing cold water on the heated iron may cause an immediate fracture. For these and similar reasons, the firemen are not permitted to go into warehouses supported by iron, _when once fairly on fire_.

Cast and wrought-iron have been frequently fused at fires in large buildings such as warehouses, sugar houses, &c., but according to Mr. Fairbairn's experiments on cast iron in a heated state, it is not necessary that the fusing point should be attained to cause it to give way.[A] He also states, that the loss of strength in cold-blast cast iron, in a variation of temperature from 26 deg. to 190 deg. = 164 deg. Fahr., is 10 per cent., and in hot-blast at a variation of from 21 deg. to 190 deg. = 169 deg. Fahr., is 15 per cent.; now if the loss of strength advances in anything like this ratio, the iron will be totally useless as a support, long before the fusing point is attained.

Much confidence has been placed in wrought-iron tie or tension rods, to take the lateral strain of the arches, and also in trusses to support the beams; but it must be evident that the expansion of the iron from the heat, would render them useless, and under a high temperature, it would be so great as to unsettle the brickwork, and accelerate its fall, on any part of the iron-work giving way: again, the application of cold water to the heated iron, in an endeavour to extinguish the fire, is almost certain to cause one or more fractures. The brick-arching is also very liable to fall, especially if only four and a half inches thick, independently of the weight which may be placed upon it, for it is not uncommon after a fire in a large building, to find the mortar almost completely pulverized to the depth of three inches, or four inches, from the face of the wall. When a fire occurred under one of the arches of the Blackwall Railway, on the 15th July, 1843, a portion of the lower ring fell down, and also a few bricks from the next ring.

Another very serious objection to buildings of this description, is that, unless scientifically constructed, they are very unlikely to be safe, even for the common purposes intended, independent of the risk of fire. In the Report of Sir Henry De la Beche and Mr. Thomas Cubitt on the fall of the mill at Oldham, in October, 1844,[B] it is stated that the strength of the iron-beams was within ten per cent. of the breaking weight. Now according to Mr. Fairbairn's experiments on heated iron, already referred to, an increase of temperature of only 170 deg. would have destroyed the whole building. It is quite clear, therefore, that so long as mill-owners and others continue to construct such buildings without proper advice, they must be liable to these accidents. In timber-floors there can be no such risk, as the strains are all direct, and any journeyman carpenter, by following good examples, can ascertain the size required; and even if he makes a mistake, the evil is comparatively trivial, as the timber will give notice before yielding, and may be propped up for the time, until it can be properly secured. In the case of fire-proof buildings, an ignorant person may make many mistakes without being aware that he has done so, and the slightest failure is probably fatal to every one within the walls. This also increases the difficulty and danger of extinguishing fires in a large building, as the only method of doing so is for the firemen to enter it with their branches, and in case of the floors falling, there is no chance of escape. On the other hand, timber-floors have repeatedly fallen while the firemen were inside the building, and they have made their escape uninjured.

In a pamphlet published by Mr. S. Holme, of Liverpool, in 1844,[C] and which contains a report from Mr. Fairbairn on fire-proof buildings, it is stated, that many people, especially in the manufacturing districts, are their own architects; that the warehouses in Liverpool may be loaded to one ton per yard of flooring; and that unless great care and knowledge are used in the construction of fire-proof buildings, they are of all others the most dangerous.[D]

The following are the principles on which Mr. Fairbairn proposes to build fire-proof warehouses:--

The whole of the building to be composed of non-combustible materials, such as iron, stone, or bricks.

In order to prevent fire, whether arising from accident or spontaneous combustion, every opening, or crevice, communicating with the external atmosphere to be closed.

An isolated staircase, of stone, or iron, well protected on every side by brick, or stone walls, to be attached to every story, and be furnished with a line of water-pipes, communicating with the mains in the street, and ascending to the top of the building.

In a range of stores, the different warehouses to be divided by strong partition-walls, in no case less than eighteen inches thick, and no more openings to be made than are absolutely necessary for the admission of goods and light.

That the iron columns, beams, and brick arches be of strength sufficient, not only to support a continuous dead pressure, but to resist the force of impact to which they are subject by the falling of heavy goods upon the floors.

That in order to prevent accident from the columns being melted by intense heat in the event of fire in any of the rooms, a current of cold air should be introduced into the hollow of the columns, from an arched tunnel under the floors.

There is no doubt that if the second principle could be carried out, namely, the total exclusion of air, the fire would go out of itself; but it seems, to say the least of it, very doubtful indeed if this can be accomplished, and if it could, the carelessness of a porter leaving open one of the doors or windows, would make the whole useless. The fifth principle shows that Mr. Fairbairn has omitted to allow for the loss of strength the iron may sustain from the increase of temperature. The last principle would not be likely to answer its purpose, even if it was possible to keep these tunnels and hollow columns clear for a number of years, which is scarcely to be expected. A piece of cast-iron pipe, one-and-a-half inch in diameter, was heated for four minutes in a common forge, both ends being carefully kept open to the atmosphere, when, on one end being fixed in a vice, and the other pulled aside by the hand, it gave way.

One of the principal objections to the kind of fire-proof buildings above described, is, that absolute perfection in their construction is indispensable to their safety; whereas buildings of a more common description are comparatively safe, although there may be some errors or omissions in their construction. Indeed, Mr. Fairbairn states in the same Report, that "it is true that negligence of construction on the one hand, and want of care in management on the other, might entail risk and loss to an enormous extent."

The following is a very clear proof of the inability of cast iron to resist the effects of fire:--