In one case, investigated by Mr. Lauder (Glasgow), the explosion occurred during the cleaning out of a large generator. Mr. Lauder held the view that the ignition of the residual gas in the generator was possibly due to a spark caused by the stirring arm striking a piece of ferro silicon which had become wedged against the top of the sluice valve. On the other hand the makers do not think this possible, and although prepared to alter the design of the machine to prevent any possibility of an accident occurring in this manner in future they are of opinion that the ignition was probably due to overheating of a piece of carbide which had been covered with sludge and which, when uncovered in the inflammable mixture of gas and air, was hot enough to cause ignition.

Another fatal case at Hackney was no doubt due, to gas which escaped from the bell of a "water to carbide" generator which produced an explosive mixture in the space between the bell and the tank. The generator had been left standing during the mealtime and when deceased returned he apparently lit his burner and, in doing so, ignited the mixture. The explosion acting downwards through the waterseal blew the bell upwards. This accident illustrates the importance of providing a relief pipe which will carry away to a safe point any excess gas which may be formed in a generator.

Mr. Paterson (Lincoln), reports a fatal accident which occurred during the removal of a generator. The generator had been standing out of use for a fortnight, the men had emptied the water out of it and were proceeding to place it on a bogie. They found it too heavy and lowered it to the ground when the bell suddenly blew off. The cause of the ignition was not discoverd, but it may have been due to movement of the bell in the generator as a result of a sudden jolt. This accident calls attention to the importance of completely clearing a generator of gas after work is finished.

A similar explosion, which fortunately did not cause injuries, is reported by Mr. Hird (Stockport). In this case the generator, which was of a portable type had been emptied of sludge and washed out and was being wheeled along. No doubt the washing with water had exposed some unused carbide with consequent generation of gas. The cause of ignition was not certain, but was attributed to a spark caused by a sudden jolt received by the apparatus when passing over some rough roadway.

Another fatal case reported by Mr. Hepburn (Birmingham West), was due to deceased man attempting to weld a defective acetylene gas holder without first taking steps to remove all traces of gas. Similar accidents have occurred before and it is. highly important that men should not attempt such repairs until the vessel has been completely filled with water and then emptied so as to replace all air-gas mixture.

Mr. Price (Engineering Inspector) investigated, with Mr. Carter, (Nottingham), an explosion which occurred at Nottingham. In

this case a small portable generator was being used for the repair of a boiler. When the oxygen supply was being turned on, the acetylene flame was blown out, and the deceased man began to investigate the cause of this. What he actually did is not known, but almost immediately the bell of the generator was blown from its fastenings and inflicted serious injuries on him. After the explosion the cover was found to be unfastened, while the fastenings were not damaged in any way, and there is the possibility that a leakage of gas-air mixture from the newly charged generator, may have been ignited by a gas flame within a distance of 7 ft. Whether the hydraulic valve was properly charged with water cannot be ascertained and there is therefore the possibility that the explosion may have been caused by a back draught of flame.

In a fatal accident which was investigated by Mr. Beard, the blowpipe was being lighted when the flame travelled through the hydraulic valve of the purifier to the generator. It is stated that the hydraulic valve was filled with water, and if this was so, it suggests that the design of the valve was not satisfactory. Attention has already been widely drawn by the Trade Journals to danger which may arise from the use of hydraulic valves of faulty designs. In one valve of this type examined recently, the seal afforded to the gas pipe was only in. when the relief pipe was beginning to blow.

Occupiers should require, when purchasing such a safety device, some guarantee that the design is satisfactory, and for this purpose makers of such devices would be well advised to issue with each valve a scale drawing showing its design. However good the hydraulic valve may be, it must be properly filled before use, and lack of attention to this may cause a fatality.

Bursting of Engine Fly-Wheel.-Mr. Price, Engineering Inspector, reports below the circumstances connected with the bursting of a steam engine fly-wheel :

A destructive accident, due to the bursting of the fly-wheel of a 120 h.p. horizontal compound condensing engine, took place in a saw-mill in the North of Scotland on Christmas Eve, 1925, as the result of which one person was killed and four others injured and much material damage was done.

The wheel was 13 ft. in diameter and weighed 5 tons. The speed of the engine was 75 r.p.m. The governor was of the standard Pickering highspeed type, driven by a 2 in. belt from a pulley on the engine shaft. Steam was supplied through a double-beat piston throttle valve mounted in a combined stop and throttle valve chest. A jockey pulley riding on the belt afforded independent control of the throttle valve spindle and was an additional safeguard in the event of the governor belt breaking. The main transmission belts (which were driven off the fly-wheel) broke, thus suddenly releasing the load on the engine which at once speeded up, but the consequent movement of the governor failed to close the throttle valve because of its defective condition. When the valve chest was opened up after the accident the seat of the upper valve was found to be detached from its original position and wedged upon the lower valve. The upper valve therefore could not close and live steam continued to pass to the engine through the annular space left by the displaced seat. This continued supply of steam was sufficient, under the "no load "conditions, to cause the engine to "race to such a speed that bursting of the fly-wheel was inevitable. The valve seats were plain cylindrical rings and were not positively secured

(e.g. by screwing or otherwise) to the valve chest, and the displacement was a direct consequence of this insecurity. This serious accident points to the necessity for systematic examination of the internal fittings of steam control gearing of steam engines, and periodical testing of the control gear.

Dangerous Buildings.-The disuse of two dangerous mill buildings has been brought about as the result of action taken by this Department. In one case the internal structure had got into a decrepit state, and on pressure being brought to bear on the owners they decided that, as the occupiers had not paid rent for some time, it was not worth while carrying out the necessary extensive repairs and strengthening. Consequently, all the machinery has been taken out of the mill. In the other case, a section of a long mill which had been leaning for some years was found to be moving slightly, and as it was considered that the shoring, which had been erected for some time, could not be relied on, it was decided that the mill was not safe, particularly as most of the manufacturing process, involving the use of heavy vibrating machinery, was carried on in the top room. The Department brought pressure to bear on the occupiers and the use of the dangerous part of the mill for manufacturing processes has now ceased and the upper part is being demolished. A third case related to a small shed type of building used as a blacksmith's shop. In this instance the occupiers moved out into suitable premises and the place ceased to be under the Act.

The weakness of asbestos-cement roofing has been repeatedly referred to in previous Annual Reports, but each year continues to bring its toll of accidents. During 1926 there were 22 instances reported of the failure of asbestos-cement roofing material; these caused 2 fatal and 25 non-fatal accidents. The cases were reported to the Building Research Board in connexion with the special inquiry which that Board have in hand concerning this material.

Fire Drills.-Inquiry was made throughout the country as to the present practice of firms in regard to fire drills. It is clear that only a very few establishments have any definite system of drills in which all the workers participate; actually only 110 such works are known to the staff and the great majority of these are in London. It must not, however, be assumed that these include all the premises in which fire drill is practised; there may be a few more which have not come to the notice of the staff.

A large number of factories have fire brigades. In some of the largest works these are manned by regular firemen who act as fire patrols; in other works the brigade is formed by a nucleus of regular firemen and a number of volunteers from various departments. In the majority of works the brigade consists entirely of volunteers drawn from the staff, and they are trained and drilled at regular intervals either by a representative from

one of the fire-fighting appliance firms or by a local fire brigade officer. These drills appear to be carried out fairly regularly in most works, and the members of the fire brigades are generally instructed with regard to arrangements for speedily evacuating the workers from the buildings.

In certain establishments where all the workers take part in periodic fire drills, the whole of the employees are not drilled at one time, but each department is drilled separately. This avoids in large factories undue dislocation of work, unnecessary excitement and commotion, and gets over to a great extent the difficulties associated with loss of wages among the piece-workers.

It is noted that there is great variation in the intervals between drills; in one or two cases the drills are weekly, and in a few annually, but the majority are at intervals of from one to three months.

Amongst the 110 firms who carry out regular fire drill there is a surprising variety in the industries represented. Letter-press printing, bookbinding and lithographing come first with 14 works; tobacco follows with 13; clothing 7; confectionery and engineering each with 6; dyeing and cleaning 5, and the manufacture of boots, cardboard boxes, indiarubber, matches, soap, paints and varnishes, printers' ink, sugar refining, metal and shoe polish, candles, gas mantles, toys, furniture and upholstery, baking and preparation of foodstuffs, drugs, pencils, photo and cinema films, spectacles, linoleum, tin boxes, fancy boxes, packing cases, oil blending, surgical dressings, brass finishing, leather, starch, worsted spinning, cotton spinning, cotton waste, paper, laundries and breweries are all represented by one to four firms.

Although there are a few really large works represented in the above list, the majority are quite moderate in size, employing from 30 to 150 workers.

It has to be recognised that in the case of piece-workers fire drills may entail some loss in wages. This can hardly be avoided if such workers participate with the other employees in the drill, but the difficulty has been surmounted in some instances by the employers making up the loss in wages, in others by allowing piece-workers, especially if adult males, to remain at work. Inconvenience and disorganisation of work is avoided in some works by arranging for the drills to take place immediately before a meal-time or other rest interval.

A somewhat analogous difficulty arises in works where processes are continuous and cannot be suddenly interrupted. In such cases those employees who are engaged in continuous operations generally remain at work; but in the case of certain rubber factories the machines are cleared about 10 minutes before the fire drill is signalled.

Directional notices as to what steps to take in the event of a fire, while not common in small establishments, are fairly general in most of the larger works carrying out drills. Such notices

are usually displayed in the various rooms and copies supplied to each member of the fire brigade. It is usual to make each foreman responsible for seeing that all workers are promptly cleared from the department of which he has charge and that the recognised means of escape are made use of. In certain of the many works where no complete fire drills are practised, the employees are required periodically to leave the premises at the dinner hour or end of the day's work by the fire escapes. This is a useful procedure as it accustoms all to the use of the emergency exits; experience shows moreover that where it is not practised the workers often remain entirely ignorant of the alternative means of exit provided for them.

The outstanding fact disclosed by this enquiry is the very limited number of factories in which fire drill, participated in by all the workers, is practised. Outside London the number is particularly small, and in the North Midland Division there is not a single works known to the staff in which such drills are carried out. The reason for this infrequency of practice would appear to be due not so much to inherent practical difficulties as to the belief, if the question has been seriously considered at all, that drills are not particularly necessary.

DANGEROUS TRADES.

Building Regulations.-This Code, which came into force on the 1st October, 1926, is limited in its scope to premises on which steam, water or other mechanical power is temporarily used for the construction of a building, or for the purpose of any addition to the structure of an existing building. Thus the Code does not apply to repair work nor to buildings, and there are many such, on which no mechanical power is used. The Regulations have not been sufficiently long in force to enable any very definite idea to be formed of their beneficial effects, but, as the code was based on prolonged conferences with representatives of the employers and workers in the building industry, it has been found that many of the requirements were already familiar to the persons responsible, and quite substantial compliance in many cases was noted almost immediately the Code came into force. Tribute must be paid too, to the help that has been afforded by the Master Builders' Associations, who have done all they can, by circular and otherwise, to bring home to their members their new responsibilities.

As there are a large number of the buildings to which the Regulations apply in London, the following remarks by two Inspectors, who have done a good deal of intensive inspection, are quoted :

Mr. Kerr (West London).—It is encouraging to find a real interest taken by some of the general foremen and foremen scaffolders employed on buildings subject to the Regulations. In one or two jobs these men were exceedingly particular in conforming with the requirements, and it needed only a helpful