Weak infantry patrols can neither break down this resistance nor create the necessary opening through which the leaders can reconnoiter in person. Stronger forces are requisite, and “reconnaissance companies” may have to be sent out toward the enemy to serve as a support for the patrols, to reinforce them when necessary, and to constitute natural collecting stations for messages. “Reconnaissances in force” are the result of these endeavors to obtain information,[260] for the defender will not reveal his dispositions unless the attacker threatens an attack. Reconnaissances in force are especially appropriate in this case, since the information obtained in regard to the position and strength of the enemy can be utilized at once. (Par. 134 German F. S. R.). [260] See _Taktik_, IV. p. 214, et seq. The results of the reconnaissance in force made at Neuville aux Bois were very unsatisfactory. In France great importance is attached to forcibly gaining information by means of detachments of all arms which also prevent hostile reconnaissance. In minor operations the French send out infantry detachments, which, from secure hiding places, pick off observers, screen the position of their own force, and prevent the enemy from using covered avenues of approach. However, these very patrol combats may cause the commander to come to a false conclusion in regard to the hostile position. If the cavalry reconnaissance has determined that the enemy intends to accept battle within a particular area, the details of his intentions must be obtained by local reconnaissance. Then the commander will wish to know whether or not an immediate attack is feasible, or whether it is advisable to wait until nightfall for bringing up the infantry. The local reconnaissance determines where the flanks of the enemy are located; whether the position in front is the hostile main position or only an advanced post; whether the enemy has made preparations for defense; and where the hostile artillery is posted. As a rule, it will be impossible, until after the engagement has begun, to recognize a skillfully located fortified position,[261] to distinguish between the real and dummy trenches, determine the position of obstacles and estimate whether they can be surmounted with or without adequate apparatus. Then it likewise becomes necessary to find and mark covered avenues of approach.[262] In moving to new firing positions, it is important that advanced positions, masks, and dummy trenches be recognized in time. The commander of a unit on a flank should make dispositions for observation on his flank, and for permanent communication with neighboring units, even though no specific orders have been received by him to that effect. Strange as it may seem, the troops deployed on the road Gorze--Rezonville (battle of Vionville), by their failure to get into early communication with the troops which had been on the ground for some time, neglected to take