When the German forces advanced to Paris in the closing months of 1870, the plan pursued with the telegraph was as follows: The ordinary commercial and railway telegraphs were gradually extended over the frontier into France, as the German armies advanced. The field or _étappen_ telegraphs maintained communication between the base of operations, the ammunition dépôts, and the advanced columns of the various army corps. When the sappers and miners had pushed on to the vicinity of Paris, the ubiquitous wire travelled with them. The materials used were light and simple; the operators employed to transmit and receive messages had been trained in the state establishments; and headquarters were kept instantly informed of any observed movements on the part of the French. The telegraph was indeed in constant use by the Germans--for arranging the transport of ammunition; for hourly communication with the commissariat; for directing the conveyance to Germany of sick and wounded, as well as prisoners; for regulating the traffic on the field railways; for maintaining unbroken connection between the troops, which formed a belt of ninety miles' circumference around Paris; for summoning reinforcements to any point where suddenly needed; and to send news of any gap in the continuity of the immense ring of soldiers encircling the beleaguered city. If any evidence were needed of the invaluable services rendered by the electric telegraph in the war just noticed, it was furnished by M. Von Chauvin, who attended before a Committee of the House of Commons on Postal Telegraphs in 1876. He stated in distinct terms that the war could not have been carried on without this potent aid. Our own English system of war telegraphy, organised at Chatham, has been improved from time to time. Light iron telegraph poles are provided, to support insulated wires. There is a travelling office on wheels for the operators; while the materials are carried in specially constructed wagons. So strong is the wire that wheels may go over it; and therefore the line is laid above ground or _on_ the ground according to circumstances. Spikes of peculiar form enable the wires to be hung on trees or walls to meet the contingencies of towns and villages. The nucleus of the staff of operators is a small body of Royal Engineers, under their own officers, comprising about fifty military men, with occasional assistance from others--well organised into superintendents, inspectors, clerks, linesmen, storemen, artisans, and labourers. The wagons for materials contain drums on which the wire is coiled; this is unrolled as the wagon moves on, which is as fast as the operators can lay the line. At the present time, ten thousand miles of prepared wire are said to be kept in store, ready for any exigences.