Amos A. Fries, Chemical warfare (1921)
“ The signal smokes by day will be displaced at night by brilliantly colored lights which will have the same meaning as similarly colored smokes during the day. Thus, literally, smoke in the future will be the cloud by day and the pillar of fire by night to guide the bewildered soldier on the field of battle with all its terrors and amidst the confusion, gas, smoke and dust that will never be absent while battles last. ”
