Cases of motor-lorries being "ditched" or stuck in thick and squelching mud at the side of the road are not unknown, though, of course, during the succeeding winters they were less prevalent than in 1914, through greater expertness, born of continued practice and more experience on the part of the drivers in handling their lorries. Still, the liability to stick in a convenient ditch is always present in bad weather on narrow country roads, and during the temporary pause of the lorry thus caused, the greater the effort exerted by the driver and engine to extract it, the more briskly the rear wheels revolve in the mud without advancing the lorry, and the worse becomes the "ditching." Non-skid chains that can be easily fitted in such an emergency have proved themselves an invaluable aid. With these securely fixed on the offending wheel or wheels and another lorry in front, attached to the defaulter by towing chains, the latter is soon on the crown of the road once more and able to continue its journey. All convoys are run strictly in accordance with orders, and the cardinal principles are briefly that lorries running in convoy must keep twenty-five yards, approximately, apart and not travel at a greater speed than ten miles per hour, even this being reduced on passing troops on the march or going through a village or town. Since the convoy must keep together, its speed must therefore necessarily be the speed of its slowest vehicle, and the method of keeping a convoy together and thus preventing lorries taking a wrong road or getting lost is a very simple one. In addition to the driver, each lorry has a driver’s mate, who rides inside the body of the vehicle just behind the tailboard, and as soon as the vehicle immediately in rear of him stops, he signals to his driver to pull up. Thus the driver of the lorry immediately in front will receive the same message from his mate, namely, that the lorry immediately behind him has stopped, and in a very few minutes the whole column of vehicles will be at a standstill. Instances of such a stoppage occurred in the event of a lorry in the column suffering from any mechanical breakdown during the course of its journey or meeting with a mishap of any kind on the road. It is also the job of the "look-out" man in the back of the lorry to warn the driver, by means of the communication cord, when vehicles approaching from the rear desire to overtake the convoy, so that the driver can be immediately warned to pull off the centre of the road and thus enable the faster-moving vehicle to pass. The idea of the communication cord is a good one; on these occasions it makes outbursts of fiery language from Staff officers in cars, who are in a hurry, superfluous.