Of the two-flag signals we have three varieties. Should the burgee, Fig. [307], be uppermost it constitutes what is termed an attention signal; thus the hoisting of B.D signifies, "What ship is that?" If the upper flag be a pennant C.D.F. or G it is a compass signal; thus G.F means west-north-west-half-west. If a square flag be uppermost it is an urgency signal; thus, N.C signifies "am in distress," or N.J "am driving, no more anchors to let go."
Signals made with three flags are not classified according to the upper flag; they relate to subjects of general inquiry or communication of news. In the lower portion of Plate XXIV. we have given five examples of these. Fig. [330], flags B.P.Q, asks "Do you wish to be reported?" while the hoisting of P.D.S, see Fig. [332], replies, "Report me to Lloyds' Agent." Fig. [333], H.V.F, asks, "Do you want assistance?" while Fig. [334], G.B.H, enquires, "Has any accident happened?" Fig. [331], made up of flags V.K.C, gives the reassuring answer to both enquiries—"All safe." As weather signals, we find "barometer rising" indicated by G.F.W; "barometer falling" by G.H.B; and "barometer standing," by G.H.C. Fine weather is prognosticated by the group H.M.S; a breeze off sea is foretold in the combination H.S.V; and a breeze off land by H.S.W.
Signals composed of four flags are divided into different sections again, according to the form of the uppermost flag employed. If this upper flag be either of the pennants C.D or F, it indicates that the signal is what is called vocabulary. If the upper be the burgee—the letter B of the code—it is a geographical signal; thus, any vessel beating up channel and seeing Fig. [325], made up of B.D.T.F, hoisted from a lighthouse, would, even if uncertain before, know their position, as this signal is the one specially assigned to the Eddystone. Fig. [326], the letters B.D.P.Q, signifies that the vessel flying it hails from the port of London, while B.F.Q.T. is Edinburgh, and so on. All names of ships are expressed by four letters, thus N.V.B.Q is the code signal (Fig. [327]) of the steamship Germanic; M.N.D.L (Fig. [328]) that of the Hesperus; and Fig. [329], made up of G.R.C.T, is the special grouping assigned to H.M.S. Devastation. All these names are recorded in the Shipping List, so that two vessels passing each other in mid-ocean are able at once to determine each others' names if within sighting distance of the flags run up. Should we see a stately liner coming to port, flying M.T.L.Q, we recognise that it is the Australia of the great Peninsula and Oriental Line, but if she runs up L.H.T.B then she is the Orient Company's boat Orotava. Some names occur frequently, thus other Australias, belonging to various owners, are distinguished by the code signals R.L.H.V, J.T.G.K, M.P.F.C, M.Q.N.G, M.T.W.D, W.F.T.N, etc., etc. Figs. [355], [356], [357], [358], [359] are all code signals of various Australias. While the Peninsular and Oriental Company has also a Victoria, K.M.Q.F., they have no monopoly of the name. There are numerous other boats of that popular designation, but even when vessels have the same name no two vessels ever have the same code letters assigned to them. Other Victorias, for example, are differentiated, as W.Q.M.N., L.S.H.R, K.P.G.Q, M.K.C.H, M.S.P.B, M.Q.C.J, L.D.F.H, T.R.B.N, K.J.H.P, T.D.R.F, etc., etc. Figs. [350], [351], [352], [353],
[354] are all Victorias; and Figs. [360], [361], [362], [363], [364] are the flag-signals of various Britannias. Our readers will see at once how distinctive they are. Figs. [335] to [349] inclusive are the special flags of well-known steamships of the Peninsular and Oriental, the Orient Line, and the Compagnie Générale Transatlantique.
Should the vessel be a yacht, it is the Aline if she shows the flags P.W.N.D; the Star of the Sea if her signal is T.N.B.H; but if it is the Meteor we shall be aware of the fact from her hoisting the four flags L.C.T.P. The flag signal of the Valkyrie is L.F.M.G.
Applications for the allotment of a code-signal, for the purpose of making ships' names known at sea, should be made, if of the United Kingdom, to the Registrar General of Shipping, Custom House, and, if belonging to a Colony, to the Registrar at the port to which the vessel belongs. If a ship to which this International Code Signal has been alloted is reported wrecked, lost, or sold to a foreigner, and her register is in consequence cancelled, the signal letters allotted to her are also cancelled, so that if the ship is afterwards recovered or re-purchased from foreigners, either in her original or some other name, new signal letters will be necessary, and the owner must make application anew for another allotment, as the signal letters the vessel originally bore may have been in the interval re-allotted.
The flags to be hoisted at one time never exceed four, and it is an interesting arithmetical fact, that, with these eighteen flags, never using more than four at a time, over seventy-eight thousand different combinations can be made. With these flags, only using two at a time, 306 different arrangements can be made, while by using three at a time we get 4,896 possibilities, and by using four at a time, we can make 73,440 changes; a total in all of 78,642 variations made from these simple elements. Marryat's code, prior to the introduction of the International, being the one most in use, twelve out of its sixteen flags were, to save expense, incorporated in the new code. Their significance was, however, entirely changed. Marryat's flags, too, were numerals, while the International code, as we have seen, has its flags named after the letters of the alphabet.
Proposals are in the air to add eight new flags to the code, the X, Y, and Z, and the five vowels, since it is held that even the great number of combinations now possible may in time not suffice. The reason for the absence of the vowels is a somewhat curious one. Directly vowels are introduced we begin to spell words, and it was found that amongst the thousands of combinations possible, would be presently included all the profane, obscene, and otherwise objectionable four-letter words of the whole world. To hoist D.B.M.N could offend no one's susceptibilities, but to
run up the signal D.A.M.N in response to an enquiry is quite another matter, and it must be remembered that as this code is used by all civilised nations, a word that is merely meaningless in one country might be most offensive in another. An English Captain might hoist as a necessary signal J.A.L.P. or F.L.U.M. and see no possible objection to it, but "jalp" or "flum" might to the people of some other nationality carry a most atrocious significance.