On a very dark night a modification of the system described in section 71 of the latter book may be employed with advantage. Half a dozen assistants, with luminous discs, both on their chests and backs, are provided, and, when the guide has determined on the line, these assistants are placed on it facing towards the guide and covering each other. As the force advances each assistant in turn moves to the far end of the line and covers again on the others. With well-trained assistants a rate of advance of about half to three-quarters of a mile per hour may be counted on. In enclosed country if the fences run parallel to the line of advance they are a great help to the guide, otherwise they increase his difficulties. Fences, as a rule, must be passed at gateways or gaps, and this necessitates moving in a zig-zag direction. On a starlight night the following method has been used with success. A star to march on having been chosen, the company is halted, and an officer, with a couple of scouts, each provided with a pocket electric lamp, are sent on to find the best point of passage in the fence; when this point is found an electric light is shown, and the company marches on it. In broken ground it may sometimes be necessary to post one of the scouts with a light as an intermediate point. If the lamps are carefully handled there is but little risk of their being observed from the front. Provided that a suitable star is visible, the direction can be maintained without difficulty. If there are no stars, and the fences do not run parallel, the only means of guiding a column is as follows:— The company is halted while the guide moves on to the next fence by the method previously described for open country. On reaching the fence one assistant is posted to mark the spot, while the guide and the others search for the best point of passage. The company is then brought up to the selected spot, passed through the fence, and again halted. The guide then returns to the point at which the assistant was left, and from it lays out his line to the next fence. This is, of course, a very slow method, but it gives accurate results. Special care must be taken to see that the company is protected by scouts during the whole operation. _The Assault._ If, after the position of deployment has been reached, the enemy opens fire, the company must continue its advance until near enough to charge; under no circumstances must the fire be replied to. When the actual assault takes place the second line—and the third line, if there is one—will be halted to await developments; should their assistance be required they will act in prolongation of the first line, and strive to envelop the enemy.