Against the proposal to introduce road traction engines for use in war, it will naturally be suggested, ‘But we have the field railway, on the metal rails of which ten times as much work can be done as is possible with the traction engine on ordinary roads—even under the most favourable conditions!’

It is necessary to repeat here what has already been said, viz. that a future war, entered on by two great states as a fight for existence, will be much more energetically carried out than formerly. And the population of the countries which may be the seat of war now know what is at stake. Many a Hotspur holds up as the ideal way of waging war that adopted by the Russians with such success in 1812. Though nowadays such drastic measures may possibly not be employed by civilised states, it will be necessary in future to be prepared at the outset of a campaign in an enemy’s country for such a vigorous resistance as that which the French only began to adopt towards the end of the war of 1870-71 (by destroying railway bridges, lines, tunnels, as has been done in the present South African war).

The store of field railway material held ready in peace time will therefore barely suffice for completing and renewing the destroyed railways; such repairs may also take a long time to effect, and in the meantime road transport carried on by means of traction engines may be of the greatest value. This use of them alone ought to! recommend them as worthy of being included among the war material, of which supplies are prepared beforehand in peace time.

Supposing the supply of field railway material to be used up for repairing the railways, there is still the large amount required for siege operations to be remembered, which is not likely to be all procurable from home; and if it could, its transport from home to its destination would necessarily hinder the forwarding of other equally important war material

Campaigning in an enemy’s country means always some reliance on finding local means of transport, which is promptly requisitioned. In addition to horses, carts, wagons, etc, nowadays it is probable that the invader will be able to requisition the field railway light railways, tram lines, eta) now so commonly used for agricultural, mining, and other industrial purposes, that one may rely on finding it everywhere, except within a day or two’s march of a fortress, whose garrison will have brought it into safety.

For collecting a supply of such material (rails, eta) where the engineer or the artillerist requires it for his siege operations before a fortress, the traction engine may be employed with advantage. The demand for horses, especially at every halt in the forward march of an army, is so enormous for the establishment of magazines of food and forage as well as the transport of guns, ammunition, etc., that not a horse will be available for transport of field railway material [Kastenhols, Die Belagerung von Belfort, 1870-71: Berlin, 1878, pt. ii. p. 88.].

The part which will be played by the field railway in future siege operations is clearly indicated by the following extracts from an essay on the subject by Major Tschilkert of the Austrian army:— ‘The field railway has a gauge of only 1 metre, its iron truck will carry guns of ' 6 tons weight (15 cm. cannon and 21 cm. mortars), two strong horses will draw it, even up gradients of 1 in 10 metres, strong stays (brakes) prevent it running back, and curves of 5 metre radius allow of rapid switching off into the battery positions; with the help of a special slide mount, the heaviest siege guns can be got on or off the truck, and moved on the rails over gradients of 1 in 10 metres to their platforms. With a railway of only 90 centimetres width laid in the trenches and covered ways and worked by manual labour, supplies of ammunition, etc., can be rapidly got up and distributed under cover night and day'.

Major Tschilkert adds: ‘Future siege operations will know no difficulties in gun transport The field railway transforms the whole terrain before a fortress into an easily-crossed communication space (leicht uberschreitbaren Kommunikationsflache). Roads before fortresses have lost their value'. But this brilliant future predicted for the use of rail tracks before fortresses, presupposes means for collecting and bringing up the railway materials scattered about the country (rails, chairs, sleepers, etc.), so that the traction engine employed in this work and the field railway are not only not competitors but allies—the work of one supplementing and completing that of the other.

It would rightly expose one to the charge of being prejudiced in favour of the road traction engine to assert that it could haul guns into position in the batteries without the aid of rails. That could only be done under specially favourable conditions—firm and not too uneven ground, with protected approach. The employment of the traction engine in such cases will be confined, as a rule, to well-made roads; away from these, and on soft ground, the engine could only be employed by being itself first driven over the ground, and then used as a fixed engine to wind up the load by means of the cable. The work in this case will be slow, but not so slow as when horses or men are employed.

The use of a metal rail-track in connection with cable haulage by the traction engine is almost imperative when the ground is very soft In this case the line has the advantage of distributing the heavy weight over the sleepers, which for this purpose should be made broad. Further, the trucks or trollies can be so used that by coupling several under the load, the weight is distributed over a large number of wheels.

In combination with rails, the traction engine, used as a stationary hauling engine, with steel cable of 1000 yards length, if necessary, and rollers, can haul, or rather wind, guns over difficult and uneven ground, and up considerable gradients to high positions. For hauling loads on level ground it is Also possible, in case of need, to run the traction engine itself on rails; and for this purpose they are now constructed so that the wheels can be changed, and those for use on rails adapted to fit the gauge of the particular line to be used. The material necessary for this purpose weighs about 1 cwt., and the time required in effecting the change is about two hours.

It is unnecessary to insist on the importance of an army in an enemy's country being able to rely on its own engines in order to make use of the railways, as the opponent will take care not to leave his behind.

It is often possible to employ mixed transport by means of road engines on the country roads, with a train on rails following it But in this case, in order to avoid unloading, it is necessary that the vehicles for use on the road should be carried on the under-wagons or trollies, of which, therefore, a supply should be kept ready in peace time.

Of late, in places where the local conditions are favourable, for instance, where waterfalls are available, electricity is taking the place of steam for use on field railways, and the well-known firm of Arthur Koppel, 96 Leadenhall Street, London, has worked out a system in which, by means of specially cleverly constructed electro-motor engines, the conductors can be so quickly mounted, that the line can be constructed as rapidly as any other kind of field railway [Zeitashrift fur Elektrotechnik, 13th February 1898]. For military purposes there is no occasion to give the preference to electricity as motive power for field railways, as the mechanism required is too complicated, and the weight to be carried too heavy. But with the multiplicity of stations for supplying electric power for lighting and other purposes, there is no doubt electric power will be used for military purposes in war time when available.

For load transport on rails electric power offers many advantages, for military purposes, over cable traction, especially as the latter is often greatly limited as regards the length which can be used. But it is not to be expected that water-power engines or steam engines will be available just where the electric field-line is required for arming the batteries. In such cases the road traction engine could be used admirably as a dynamo carrier for supplying electricity. Several traction engines specially constructed and fitted could be used in such cases, either to deliver the electricity direct for driving power, or for charging accumulators. Naturally this entails the use of electric locomotives for the lines.

Although the traction engine carrying a dynamo has hitherto been used almost exclusively for lighting purposes, it is possible to imagine conditions in which it would be desirable to use it for transmitting power.