In defensive positions, which are held for a prolonged period, it is, of course, practicable to establish telephonic connection with the most advanced line. This was, for example, the case in the Japanese 10th Division on the morning of March 3rd, 1905 (Mukden). On this occasion the division commander in rear was informed by telephone of the presence of wire entanglements in front of the Russian position, and permission was asked and granted to postpone the attack. Until recently, both signal and wig-wag flags were used in Germany.[253] The signal motions are made in an upright position, the Morse code, which is rather difficult to learn, being used. This method of signaling permits communication to be kept up within a radius of 7 km.; moreover, it can be used at night and in combined land and naval operations. The wig-wag signals are easily learned and entirely sufficient for communicating over distances within 3 km.; they also permit information to be despatched rapidly, as abbreviations are employed for certain frequently recurring movements. These signals possess the additional advantage that they can be made by a man while in a prone position.[254] Wig-wag signals are a very effective means of communication and will rarely fail.[255] [253] _Jahrbücher für Armee und Marine_, June number, 1906, and March number, 1907. [254] Signals with wig-wag flags can be made by a man lying flat on his belly or on his back; this is, however, frequently impossible with outstretched arms and the sender must be content to make the signals by grasping the staves of the two flags in the middle, then placing them in appropriate position relative to each other (for example in making the letters, d, e, k, l, p, u). [255] The signals prescribed in par. 11 German I. D. R. are very effective if made with wig-wag flags; if made with signal flags they require constant observation, without, however, precluding mistakes. For example, when given with signal flags, the signal “halt” - “h, h, h,” (.... .... ....) is frequently confused with the signal “the assault is about to begin” (... ... ...). This mistake is not so apt to occur when wig-wag flags are used. When General Stakelberg, after his right flank had been turned at Wafangu, sent orders to withdraw to General Gerngross, the commander on the left flank, it took the officer who carried the order through this mountainous country, nearly an hour to cover the 5 km. which separated the two commanders. An order sent by means of wig-wag flags could have reached the leader in question within a few minutes.