Rules, however, cannot be laid down for their conduct. The Regulations indicate, shortly, that attention must be paid to the transport of sufficient ammunition and supplies, and here, indeed, move in the right direction. It is absolutely indispensable that a cavalry mass destined to carry out such an enterprise should be independent of what it may find in the country and be perfectly free of movement. The supply and ammunition columns, however, which accompany it, must also be so mobile that they are able to follow the troops closely, even at a rapid pace, as otherwise they will run the danger of falling into the hands of the enemy. The whole force designed for the enterprise must be able to advance rapidly as a concrete whole, and should not be allowed to take up too much room. Resources found upon the enemy's lines of communication and magazines captured must be used for the sustenance of the troops as far as possible. It will then be able to reserve the supplies carried for critical times or for a further turning movement. Any of the enemy's supplies which are not used must be ruthlessly laid waste. His railways and magazines, particularly any important engineering structures, must be thoroughly destroyed, the necessary explosives being carried in sufficient quantities. In contrast to Stuart's raids, however, one must count on meeting not inconsiderable bodies of the enemy's communication troops, which will probably be capable of rapid reinforcement. This entails corresponding preventive measures. Hostile cavalry sent to secure the safety of the communications will generally have to be attacked in a determined manner. It may sometimes, however, be more advantageous to avoid it by rapid marching. For the rest, the factor of surprise is of decisive importance. Should the enemy early become aware of the approach, he will generally be in a position to bring up fresh forces, often by rail, and thereby imperil the success of the whole undertaking. Under such circumstances a covered approach, perhaps by night, careful screening, and the interruption of the enemy's telegraph-lines and transmission service are matters to which special attention must be paid. It is also a matter of consideration in the attack on communications and railways to destroy them at a sufficient distance above and below the objective by means of detachments deflected for that purpose, so that the enemy may be prevented from bringing up reinforcements. If the direction of the attack is fixed upon and assured, and if approach and deployment have been successfully effected unobserved, the attack must from the first be carried through with sufficient firepower and energy to allow the enemy no time for reflection.