number of vehicles which she required for such an emergency as the present. No subvention scheme had been possible, but a certain number of lorries had been purchased directly or indirectly by the Government from Germany, England, and other countries during the two or three years preceding the war.

Italy manufactures a limited number of admirable industrial vehicles, but the conditions have not favoured their extensive purchase by the home market. The Italian Government was consequently obliged, during the Tripoli campaign, to purchase outright some hundreds of lightly constructed lorries suitable for working over loose sand. The United States possesses very great facilities for the manufacture of industrial motors. Up to the outbreak of war, however, she had not definitely attacked the European markets, as she had done in the sphere of the cheaper type of touring car. The best American industrial models indicate very clearly the influence of British designers. The American manufacturer is able to rely upon a very considerable home demand, but this is limited by the inadequacy of the roads at any considerable distance from the principal towns. His future consequently is probably dependent still more largely on a big export trade.

The state of affairs briefly indicated above leads naturally to consequences of the highest importance in connexion with the subject under consideration. In the first place, it followed that, at the outbreak of war, the Governments concerned could not limit themselves to the requisitioning of vehicles of definite types, but were compelled to commandeer any presumably sound machine of fairly suitable carrying capacity. This meant a definite interference with ordinary trade; but, while some users were deprived of their vehicles against their will, the trade of others was so far affected as to make their existing delivery system more than adequate. The result was that in the early stages matters were fairly evenly balanced; and, so far as Great Britain was concerned, the action of the War Department did not cause any great inconvenience in commercial circles. A point which is perhaps of more consequence is that, when a fleet is made up of vehicles of all makes and

types, the difficulties of maintaining it in service are immeasurably increased. Each separate type of vehicle must be supported by a supply of spare parts suitable for employment in the event of breakdown. If these spare parts are not already available, it becomes necessary to place orders with the vehicle manufacturers for their supply. It is of course impossible to devote machines or shops to the production of parts of obsolete models without seriously affecting the output of new and complete cars. Moreover, the use of mixed fleets necessitates the employment of a staff much larger than would be necessary if the cars were of uniform type.

The second important consequence of the conditions obtaining at the outbreak of war was that the Governments of all the belligerent countries were compelled to make prompt endeavours to arrange for a continuous and large supply of new vehicles either from works within their own country, or else by import. Manufacturers experienced in the production of motor lorries designed to carry loads of about 30 cwt. to 3 tons were in most instances required to reserve their whole output for delivery to Government. They were therefore unable to execute orders placed by their agents or by customers whose original vehicles had been requisitioned.

In France, all the suitable motor factories were completely mobilised, and the duties for which they were best fitted promptly assigned to them. The action taken in Great Britain was to some extent similar, but naturally, under our system of voluntary service, did not involve the enlistment of the men continuing to be employed in the factories. Meanwhile, the Russian Government, not having at its disposal suitable facilities for the manufacture of vehicles at home, began to place large orders with British manufacturers whose products had not been earmarked by our own War Department. For a time, Great Britain was in the position of supplying its own immediate needs, and assisting to make good those of all its allies. It soon became evident, however, that our unaided resources would not prove equal to the strain. First the Russian and Belgian Governments, then the French, and lastly the British supplemented the fleets immediately obtainable by placing large orders with manufacturers in the United States. In the aggregate,

tremendous encouragement has been given to American builders of industrial motor vehicles; and there is little doubt that at the conclusion of the war the permanent output of these firms will be enormously greater in proportion to the British output than it was in the summer of 1914.

While these statements apply mainly to the heavier class of motor vehicle designed originally for the carriage of goods or for public service work, it must not be imagined that the touring car and the motor cycle industries remained unaffected. In order to convey some impression of a general character, it would be advisable at this point to consider briefly the principal uses to which motor vehicles are put in time of war.

The introduction of mechanical transport has led to a revolution in the methods of the Army Service Corps. The transport and supply columns which link up the railhead with the distributing points in the immediate neighbourhood of the front are now formed entirely of motor vehicles. Generally speaking, the type selected is a self-contained lorry capable of handling a useful load of about 3 tons, and on level roads of attaining a maximum speed somewhat over 20 miles per hour. If we assume that the average speed in convoy does not exceed 10 miles per hour, it follows that a fleet of 100 motor lorries can in the course of four hours bring up 300 tons of supplies to the front from a railhead 40 miles distant. The length of such a convoy would be not more than half that of a horsed convoy dealing with an equal aggregate load. This in itself is an assistance towards keeping clear the main traffic arteries behind the army in the field, but the speed capacity of the motor is a still more important factor towards the same end.

The occupation of a road by a vehicle may be measured by the product of the space actually filled by the vehicle into the time taken in carrying its load from point to point. A horsed convoy could not of course operate daily over a distance of 40 miles, carrying its load and returning empty over the same distance. To perform the work by means of animal traction would mean perhaps three convoys linking up the railhead with refilling points. At intervals along the road representing

a normal day's journey for a horse, points of junction would have to be established. At the first of these, the convoy or êchelon operating from the railhead would hand over its load to the second êchelon. On the following day, the second êchelon would again transfer its load at some point nearer the front to the third; and, if the distances were great, an even larger number would be required. For purposes of rough computation we may therefore assume that one motor convoy will do the work of at least three horsed échelons, each of double its length. The congestion on the road is thus reduced to one-sixth of what it would be if the old method still obtained.

During a period of stationary trench warfare, the difficulties of operating by means of horsed échelons linking up with distant railheads might conceivably be overcome. Directly the troops to be supplied begin to move rapidly either in advance or in retreat, the whole problem of supply and transport is enormously complicated. In the event of a retreat, the presence of congestion upon the roads may very well convert a temporary set-back into a decisive defeat. In the event of a rapid advance, the slow-moving horsed vehicles are incapable of gaining sufficiently quickly upon the troops in movement, with the inevitable consequence that ammunition and food supplies cannot be brought up punctually and regularly, and the army may well be robbed of the fruits of its first success. The whole matter may really be simplified down to a consideration of relative speeds. The time taken by a motor convoy in gaining upon infantry a distance equal to a full day's march is only a matter of a couple of hours or so. A slightly earlier start from the railhead makes it possible for the arrival at the appointed refilling points to take place at the usual time. Horsed échelons have practically no power of gaining upon troops marching rapidly. Consequently, during a continued advance, the supplies that have reached the lighter carts for distributing purposes are very likely to run short before further supplies can be brought up.

Even under the most easy and normal conditions, unless convenient railheads are in the immediate vicinity of the troops along the whole length of the line, the

presence of motor convoys alone makes it possible to supply fresh meat and bread in place of tinned and preserved provisions. Under the present system only about two days elapse between the time when cattle are slaughtered in the neighbourhood of the base, and the time when the meat from these same beasts becomes available as a hot meal for the men at the front. Assuming that the animals have been killed in the course of the afternoon, the carcases may be presumed to have been loaded on to railway trucks and forwarded to railhead the same night. Early on the following morning, the supplies are taken over by the motor convoys, which deliver them at the refilling points on the evening of that day. Next day they are cooked by the regimental travelling kitchens while on the march. In general principle, the method of bringing up ammunition is similar. Here, the advantages of the motor show themselves firstly in the reduction of congestion, and secondly in the ability to make good in the shortest possible time any temporary tendency towards a failure of supplies at any point along the front.

It will be observed that one of the principal consequences of the employment of transport and supply motors is to make it possible for an army to continue to operate at long distances from railheads. Assuming that full advantage is taken of such increased latitude of movement, problems immediately arise in connexion with the transportation of wounded men from the front to the hospitals. Without going into details as to the various stages through which it is necessary to pass before the wounded man is actually handed over to the care of a fully-equipped hospital, it is sufficiently evident that a new difficulty arises whenever the troops are operating at a long distance from their railhead. The only satisfactory method of overcoming this difficulty lies in the use of motor ambulances.

The type of vehicle usually employed for this purpose is constructed upon a touring-car chassis of moderate power and rather unusually long wheelbase. It is, in general, advisable that the rear springs of the chassis should be strengthened; but, with these two exceptions, standard models are suitable for ambulance work. The body is lightly constructed, and usually takes the form