Visual Signaling

The opening notice says the Manual of Visual Signaling, prepared in the Office of the Chief Signal Officer, is approved and published for the information and guidance of the Regular Army and the Organized Militia of the United States. The manual divides signals by period of visibility into two kinds: a transient signal disappears as soon as completed, while a permanent signal remains in view for some time. The manual says heliograph signals are transient signals, while signals made by code flags are permanent signals.

The manual describes the wand as a stick of light wood about 18 inches long and one-half inch in diameter, used for practice purposes. When only the general direction of an object can be given and it is sought for, the manual says the whole landscape in that direction to the horizon should be divided into sections, and each section scrutinized little by little until the glass has been passed over every spot. The manual says each glass will be tested for power, field, definition, and light.