Only the artillery never entirely ceased any day or night. Every shell had a personality of its own and could be identified with fair accuracy by old-timers. Most cannon were light horse-drawn field pieces which fired small shells, usually shrapnel, about three miles. The British 18-pounder,the famed French 75, and ther German "whiz-bang" 77 were all in this category. They were not too difficult to detect en route and gave the men several seconds to dive into cover. On the other hand, high-velocity pieces were hated because their projectile was thrown at terrific speed in a nearly straight line and gave almost no warning. And except for the great railway guns the howitzers were the largest of all: gaping monsters that tossed their fat shells almost straight up and down. The men called them "crumps."
The German 5.9 was also polite and gave the recipient some small time for acquiring shelter. The last part of its passage was a deep roar; one was safe if the roar lasted, but if one was in its path it descended fast and the best that could be hoped for was an extreme case of shell shock. These were called "coal boxes."
The sounds of the projectiles created a bizarre symphony. Field-gun shells buzzed in a crescendo and burst with a clattery bang. The heavies flung their black bodies like great loaves of bread (they could be seen in flight) across vast reaches of the infinite sky and approached with the roar of an oncoming express train. Over valleys they all echoed distractingly and defied prediction. Those that fell in hollows burst with terrible suddenness and a double crash. Fabulous indeed was the blast of the 30.5 Australian trench-mortar. An there were shells that screamed, shells that hissed, gas shells that exploded with a simpering pop, shells that whistled, and shells that wobbled across heaven rattling like a snare drum. Finally there was drumfire, reserved for special occasions, when all the instruments blended into one homogeneous mass of sound of such intensity as cannot be described, all bursting into jagged fragments of hot metal that slammed into the bodies of men and mules with familiar results.
The troops hated artillery more than machine guns, more than snipers, or bayonets, or even gas; for there was no fighting it, nor could much really be done to elude it.
~ From In Flanders Fields by Leon Wolff, p. 11