It was in this battle that the British for the first time introduced a new type of armored cars which proved veritable fortresses on wheels, and came to be popularly known as "tanks." These destructive engines of warfare were from twenty to forty feet long and were painted a dull drab, or some unassuming color calculated to blend with the tones of the landscape. In a dim light they suggested the giant slugs of a prehistoric age. Sliding along the ground on caterpillar wheels, with armored cheeks on each side of the head, above which guns stuck out like the stalked eyes of land crabs, their first appearance in this sector may well have created consternation among the German troops who saw them for the first time. There was something uncanny about these steel-scaled monsters that slid over the ground as it were on their stomachs, balanced by a flimsy tail supported on two wheels. Weighing many tons, when the "tank" came to an obstacle, such as a house or wall, it rammed the obstruction with its full weight, and then climbing over the debris lumbered on its way. Through vast craters and muddy shell holes and over trenches the monsters waddled along, scattering death and destruction as they advanced. The German soldiers, after the first consternation caused by the appearance of these war engines in the field, bravely attacked them; swarming over the sides of the "tanks" and seeking to batter in the steel scales and armored plates and to silence the guns that spouted fire from the head, but the daring efforts were useless and caused many casualties. Machine-gun fire was also ineffectual. They could only be disabled by a direct hit from a large gun. It is said that the Germans voiced their disgust for this kind of warfare, and protested that the British were not fighting fair! At first the Germans thought they could rush a "tank" as they would a fort, and lost heavily in such futile attacks; they could make no impression on the steel "hide" of the monsters. Once astride a trench, the guns of the tank could rake right and left, mowing down the defenders whose volleys pattered harmlessly on the steel plates of the war engine. A young Australian who served in one of these new war machines described "tanksickness" as being as bad as seasickness until you became accustomed to the constant plunges and lurchings as the "tank" encountered obstacles on its way. The Australian noted down his impressions while cruising around the German lines in a "tank." A few quotations from his diary may be of interest: