The casualty clearing station, on the other hand, having an established capacity of nearly 600 beds, has much heavier equipment and is not supposed to be a mobile unit, though it is capable of moving with the aid of its two lorries by making repeated trips. Many of the casualty clearing stations are located in huts which can be torn down and moved forward and rebuilt by the engineers and construction units. There is also in each division a sanitary section composed of one officer and 25 men, whose function it is to keep an eye on the sanitation of the divisional area, report failure on the part of units to observe the established sanitary regulations, see that the incinerators are operated, have new sources of drinking water tested, look after the bath houses on occasion, search for cases of typhoid fever, etc., among the civilian population, and, in general, make itself as useful as possible. The British army regulations are such that each officer and man must be a sanitarian and must not only observe the regulations but see that others do the same; the principle underlying this system being that "if each before his doorstep swept the village would be clean." Consequently it is not left to the sanitary section to clean up a divisional area, but rather to report those responsible for not keeping it clean. In this way every man is made a responsible party, and if the officers of any unit see that the regulations are enforced by each man, the unit will be a sanitary one. Naturally as the battalion M.O. is directly connected with the field ambulance to which he sends his cases, he is most interested in the efficiency of that unit. Since the field ambulances are under the direct supervision of the A.D.M.S. of the division, you will find the latter during a battle visiting these to see that they are operating smoothly and whether more motor ambulances, stretchers, supplies or other necessities are being provided. At the same time you will find the D.M.S. of the army visiting his special pets, the casualty clearing stations, and seeing that the evacuation of the wounded by train is working smoothly. The hospital trains are specially fitted up with beds, kitchens and dispensaries, and with nurses and a medical officer in charge. The hospital barges make the finest little hospitals that you could desire. They are the ordinary flat-bottomed square-ended Dutch barges, roofed in, and when the interior has been cleared out they form elongated covered floating boxes. Skylights in the roof give a splendid light, and the barges are wide enough to allow of two rows of beds with an aisle down the middle. The medical officer's surgery and bedroom are at one end of the barge, while the nurses' quarters are at the other.