A Lecture, Or Essay On the most efficacious means of Preserving The Lives Of Shipwrecked Sailors And The Shipwreck

21 SIGNALS IN REPLY FROM THE SHIP. No. 1.—A man in some conspicuous situation will wave his arm three times horizontally or across him to denote Yes, or ready: if he has a hat, let him take it in the band he waves. No. 2.—Three times up and down to answer No, or not ready. To render these human signals distinguishable in the dark, as a pre- parative, a blue light should be fired ; then let the signal man have a lantern in each hand ; and substitute for the flag a large well-lighted lantern at the head of the staff. This lantern should have loops on the outside behind, to receive the staff; at the back of the lantern within, a highly-polished reflector, or pieces of mirror, should be placed opposite the lens ; thick glass, cat to angular points in front, is an excellent lens, and will diffuse a light sufficient to make the operations on the shore distinguishable to those on board the stranded vessel. DIRECTIONS. Persons in charge of the apparatus must, when the vessel takes the ground, and the wind is blowing sideways along the shore, in propor- tion to the strength and obliquity of the wind, point the mortar to windward of the object at a low elevation, that the slack of the rope may with certainty fall on the weathermost part of the rigging of the wreck. When the wind blows directly on the shore, the mortar is to be pointed at the vessel ; the signal being made, it is immediately fired, and communication is gained.