Here is a little bit more on Telegraph signals, which in particular mentions the option of splitting a single hoist across more than one location, and provides some detail on answering telegraph signals. It is extracted from a letter to
The Monthly Magazine [No. 104] August 1, 1803, pp.6-9, and was reproduced in the 1805 Club newsletter,
The Kedge Anchor in March this year:
Quote:
… I have already mentioned, that flags represent the alphabet and figures: there are also the following made use of:— a cypher-flag, a substitute-flag, a preparative-flag, and flags to distinguish a message, finished, understood, not understood, or message to be answered, and a numerical-pennant. A flag hoisted alone, or under another, represents units; when two flags are hoisted, the upper represents tens; when three are hoisted, the upper-most is to represent hundreds, the next tens, and the lowest units: The thousands are denoted by balls, or pennants, as may appear most likely to be seen, inferior and superior; superior 1000, inferior 2000; as for example:
No. 1016 — Aback.
No. 2016 — Shall I leave off action?
When the substitute-flag is hoisted under other flags, it is to represent the same figure as the flag immediately above it. — For example: to represent the number 33, the substitute-flag must be placed under that representing 3. When the cypher is put under other flags, it represents the cypher; as under 3, it stands for 30.
Words not in the vocabulary may be spelt by the numerical alphabet from 1 to 25. When it is necessary to express numbers in a message, the numerical-pennant must be hoisted with the signal. Ships names are to be made with the Union-jack and the number, as in the List of the Royal Navy.
When much sail is set, or in blowing weather, it may be inconvenient to hoist three flags and a pennant at the same place; the two upper may be at one place, and the two others at another; taking places progressively, as follows : first, main; second, fore; third, mizen; fourth, gaft; fifth, ensign-staff…
All signals thrown out must be kept flying till they reach the commander in chief, and that by the ships of a squadron in succession when he is not in a position to see them when first made. In cases of doubt, a ship is to repeat the signal instead of the answering-pennant; or when any particular number in a message is not understood, it is to be expressed by hoisting the numerical pennant with the word or sentence, beginning from the first word. For example: if it was the fifth word, when the message was finished, the numerical-pennant (4) must be hoisted by the ship not understanding. The ship making signal is then to repeat that word; and if then not comprehended, to change it for one nearest and synonymous. When the cypher-flag is hoisted singly, it is to annul the signal made or making.