“Up to 1910 the reports show that there were nearly five-and-a-half million bullock carts in British India alone, and in all our wars up to date, we have had to mobilise a very large number of these carts for our line of communication work. We find that when moving in large bodies, the utmost speed we can rely upon is about one-and-a-half miles an hour. We have worked out that it takes six bullock carts to move in eighty days what one 2-ton lorry can transport in ten. The bullock carts take up twice the room on the road for a given load, and in the matter of establishment--a question which you will all realise in the time of war is a very serious one--it takes thirty-five men, drivers, artificers and supervisors to look after what one man could do with a lorry.” From these figures it will be seen what an enormous saving is effected by the use of motors, even if we only take the point of view of the feeding, maintenance and payment of the men actually employed in the transport columns themselves. The impossibility of imposing upon horsed vehicles the necessity for gaining fifty or even thirty miles in the course of a day, in order to catch up by the evening with an advancing army after leaving railhead in the morning, is perfectly obvious. The truth of the statement already made that the use of motors for transport and supply work is a necessity and not merely a convenience in modern warfare, is thus made clear, and under the circumstances, readers who are perhaps more attracted by the more showy, but less essential, uses of motors in war, will understand that a consideration of the subject of this book must necessarily be devoted very largely to the organisation and _matériel_ of the supply columns. The class of vehicle most commonly favoured for the work of feeding troops in the field is the 3-ton petrol lorry, capable of covering eighty or ninety miles in a day, and if need be of travelling under fairly favourable conditions at twenty miles an hour. Behind very mobile troops, such as cavalry, preference is sometimes given to lighter lorries rated to carry 30 cwt. or 2 tons, and capable of rather higher rates of speed and rather bigger daily mileages. Some European Powers favour for general work lorries carrying 4 or 5 tons, and in addition capable of drawing an extra 2 tons or so upon a trailer. In every case, the internal combustion vehicle is preferred on account of its independence upon frequent renewals of fuel and water supplies. However, steam tractors are often used for various classes of specially heavy work, as, for example, for drawing the travelling workshops which have to be established at the movable base of the supply columns at railhead. CHAPTER III TRIALS AND MANOEUVRES