GEOMETRICAL SIGNALS.

The Geometrical Signals are intended to facilitate the use of the Code during light winds and calms, or when, from distances, the intermixed colours of the flags are not easily distinguished, and consist of certain Forms or Symbols in place of the Flags and Pendants, as exemplified in Plate No. 6, and are as follows:

The 5 forms colored Red, which represent the numeral flags Nos. 1 to 5. The 5 forms colored Blue (or Black), which represent the numeral flags Nos. 6 to 0.

The Red Hexagon, which represents the First Distinguishing Pendant when hoisted over the number, and the Union Jack when hoisted under the number, and denotes the affirmative when hoisted singly. The Blue (or Black) Hexagon, which represents the Second Distinguishing Pendant when hoisted over the number, and the Rendezvous Flag when hoisted under the number, and denotes the negative when hoisted singly.

The Yellow (or White) Hexagon, which represents the Third Distinguishing Pendant when hoisted over the number, and the Numeral Pendant when hoisted under the number, and the Telegraph Flag when hoisted at some other mast-head, and is the answering Pendant when hoisted singly.

To avoid the necessity of an increased number of forms or symbols, the use to which the Rendezvous Flag is occasionally applied, as explained at the head of the List of Ports, Headlands, &c., is not provided for, but the Rendezvous Flag may be used in conjunction with the numeral Forms or Symbols for this purpose.

These Signals are manufactured by Messrs. Richardson & Co., of Dungaree, with galvanized iron expanders, and are so constructed that they can be distinguished from all points of the compass, yet they occupy atrifling space when not in use.

SUBSTITUTES OR NUMERAL REPEATERS.

When a number is required to be shewn, containing two or more similar digits, such as 2323 or 23232, it is necessary to make use of Substitutes or

First, Second, and Third Distinguishing Pendants, and the Telegraph Flag, are used for this purpose, as follows:

The First Distinguishing Pendant as the Substitute or Repeater of the top Flag in the hoist.

The Second Distinguishing Pendant as the Substitute or Repeater of the Second Flag from the top.

The Third Distinguishing Pendant as the Substitute or Repeater of the Third Flag from the top.

The Telegraph Flag as the Substitute or Repeater of the Fourth Flag from the top.

N.B. Illustrations and examples of the foregoing will be found in the annexed Plate.

By this arrangement every number can be made up to 99,999; but should a Substitute for the Fifth Flag in the hoist be at any time required, the Rendezvous Flag can be employed for this purpose, which will not interfere with its use in connection with Part V, as in this high denomination of numbers it must necessarily be one of Six Flags.

NIGHT SIGNALS.

The Night Signals require the use of four ordinary ship's lamps, capable of being suspended one below the other, from the gaff or other place where best seen. Four bags or pieces of red bunting must be prepared to fix upon or take off the lamps, to change their colour from white to red, or red to white, as may be required, and these bags should be easily removable from one lamp to another so as to avoid any loss of time. By this simple means there are placed at immediate disposal four white and four red lights, capable of thirty different combinations.

The system employed is founded on the Roman numerals I and V,

A Single White Light representing the Roman numeral I,

A Single Red Light representing the Roman numeral V,

and every digit of a number is made by a separate Signal, and the Distinguishing Signal is shewn when the number is completed; thus not only denoting the part of the Code intended to be shewn, but serving as a stop signal, or to denote that the digits before signalled complete the number intended to be given.

The numbers 1 to 9 and 0 are made as represented in the annexed Plate, and can be understood by the person signalled to as easily as the figures on

NUMERAL REPEATERS OR SUBSTITUTES, Showing how the 1st, 2nd, and 3rd Distinguishing Pendants and the Telegraph Flag are to be used as Substitutes or Repeaters.

as the Distinguishing Signals, and should be committed to memory to facilitate the use of the system; but it may be observed as a memoria technica, that all the Distinguishing Signals are made with four lights, and that the three combinations of lights, denoting the 1st, 2nd, and 3rd Distinguishing Pendants, are those with the two Red Lights together, thus,―

The First Distinguishing Pendant is denoted by two Red Lights above two White Lights.

The Second Distinguishing Pendant is denoted by two Red Lights between two White Lights.

The Third Distinguishing Pendant is denoted by two Red Lights below two White Lights.

Part IV, Ports, Headlands, &c., is denoted by White and Red Lights alternated.

Part V, Sentences, is denoted by three White Lights above one Red Light.

Part VI, Vocabulary, is denoted by three Red Lights above one White Light.

Part I, II. M.'s Vessels of War, is denoted by four White Lights.

The Numeral Signal is two White Lights between two Red Lights, denoting that Numerals alone are intended.

The Cancelling Signal is two Red Lights above one White Light, forming No. XI, to be used when it is desired from any cause to cancel the previous Signal made.

Two White Lights, as an Answering Signal, is the Affirmative.

One White Light between two Red Lights, as an Answering Signal, is the Negative.

One Red Light between two White Lights, denotes that the Signal is not understood.

It is very desirable the answering ship should repeat the Signals made, but as this may not be practicable from the want of the necessary lamps, the affirmative Signal, or a single white light, shewn by the answering vessel, will denote that the Signal has been made out, and the vessel signalling must not vary the lights she has hoisted until they have either been repeated or the affirmative light has been shown.

But since there may be much uncertainty as to the exact position of any vessel with which communication is desired, it will be necessary, in the first instance, to give a signal sufficiently bright to command immediate notice. For this purpose a flash made by gunpowder, the burning of a piece of tow dipped in turpentine, or indeed anything calculated to make a brilliant light for a short period of time will answer, and this blaze or flash should be