TANK WARFARE. The Story of the Tanks in the Great War

Opening a loophole, I looked out. There, some three hundred yards away, a round, squat-looking monster was advancing; behind it came waves of infantry, and farther away to the left and right crawled two more of these armed tortoises.
So we had met our rivals at last! For the first time tank was encountering tank!
The 6-pounder gunners crouching on the floor, their backs against the engine cover, loaded their guns expectantly.”