ii. External communications, which are those formed as a temporary

measure to link up artillery with infantry.

2. The means of communication available for horse and field artillery are given in Sec. =149=.

3. The signalling personnel allowed is laid down in War Establishments. This establishment is based on the principle that signalling personnel is required for the purpose of providing communications downwards, _i.e._, with subordinates, and laterally, _i.e._, with equals.

To enable commanders of artillery brigades to carry out this principle they must be able to communicate with brigade stations of the divisional signal service as well as with their subordinates. The standard of efficiency of a proportion of the signallers must therefore be equal to that required of the divisional signal service. On the other hand, as long distance work is not needed within the batteries, the standard required of their signallers need not be so high.

The signalling personnel is therefore divided into two classes--

i. Brigade signallers. ii. Battery signallers.

4. As it is usually of importance to ensure the continuity of communications when once they have been opened between any two points, alternative methods should be established, if possible. To enable this to be done it is essential that men employed on the service of communication should be capable of acting in any of the capacities laid down for the classes to which they belong. All signallers should also be capable of acting as despatch riders, since it will often be quicker to send a message in this way than by signal. Instructions for training despatch riders are laid down in Signal Training, Part II.[43]

[43] In course of preparation.

=247.= _Internal communications._

1. For communicating between brigade headquarters and the headquarters of batteries and ammunition columns an establishment of brigade signallers is provided as an integral part of brigade headquarters. These men should be fully qualified signallers as laid down in Training Manual--Signalling.

This establishment has been calculated on the assumption that communication with one battery at least will be more conveniently carried out verbally or by message. Communication by telephone or visual signalling will not, therefore, be required with more than two batteries, orderlies being used to communicate with the brigade ammunition column.

The officer in charge of communications at brigade headquarters is responsible for allotting the brigade signallers to batteries for the purpose of maintaining communication between them and brigade headquarters in accordance with circumstances.

2. Communication within the battery from the battery commander to his guns and observers will be carried out by the battery signallers. These battery signallers are maintained solely for purposes of communication within the battery. Their training is limited to the use of semaphore, telephone and buzzer.

Communication may be carried out by means of:--

(_a._) Telephones. (_b._) Semaphore. (_c._) Orderlies.

For the purpose of maintaining communication between a battery and its observing station, four signallers are necessary, two at each station. They should be provided with telephones and flags, so that alternative means of communication may be available.

Semaphore signalling is the most rapid system of visual signalling with small flags. (_See_ Sec. =201= (4).)

The best way of utilizing semaphore signalling is to employ two sets of signallers, each pair having different coloured flags. Those with the same coloured flags should communicate with each other only.

In sending orders, or the result of observations, by signal the abbreviations laid down in Sec. =201=, will be used.

=248.= _External communications._

1. Effectual co-operation between artillery and infantry depends largely on the receipt of timely information. An efficient system of communication is therefore very important.

2. A personal exchange of views between subordinate infantry and artillery commanders is likely to produce the best results in a combined tactical operation. If unable to remain in the vicinity of the infantry commander, the artillery commander should be represented by an officer (_See_ Sec. =153= (7).)

3. No rules can be laid down as to the means by which communication is to be maintained between this officer and the artillery commander.

If circumstances are favourable communication may be maintained by the brigade telephone or by visual signalling, but as the infantry commander will usually change his position as the fight progresses, it may be necessary to rely on orderlies, or a combination of orderlies and telephone or visual signalling.

4. It may be possible to arrange direct communication between the artillery commander and advanced observation posts, with a view to keeping him informed as to the progress of the attacking infantry and the effect of the artillery fire. (_See_ Sec. =153= (11).)

The means of communication which can be employed will depend on the nature of the country.

Visual communication will usually be inadvisable on account of the difficulty of finding positions which are invisible to the enemy, and the telephone may be expected to give the best results. When no artillery telephone is available the possibility of sending information of equal importance to the artillery and infantry through the infantry communication service should be kept in view. It must be borne in mind that a message sent by orderly will take an appreciable time to reach its destination.