After the defeat of the British at Chelmsford on that fateful Wednesday Lord Byfield decided to evacuate his position at Royston and fall back on the northern section of the London defence line, which had been under construction for the last ten days. These hasty entrenchments, which would have been impossible to construct but for the ready assistance of thousands of all classes of the citizens of London and the suburbs, extended from Tilbury on the east to Bushey on the west, passing by the Laindon Hills, Brentwood, Kelvedon, North Weald, Epping, Waltham Abbey, Cheshunt, Enfield Chase, Chipping Barnet, and Elstree. They were more or less continuous, consisting for the most part of trenches for infantry, generally following the lines of existing hedgerows or banks, which often required but little improvement to transform them into well-protected and formidable cover for the defending troops. Where it was necessary to cross open ground they were dug deep and winding, after the fashion adopted by the Boers in the South African War, so that it would be difficult, if not impossible, to enfilade them. Special bomb-proof covers for the local reserves were also constructed at various points, and the ground in front ruthlessly cleared of houses, barns, trees, hedges, and everything that might afford shelter to an advancing enemy. Every possible military obstacle was placed in front of the lines that time permitted, abattis, military pits, wire entanglements, and small ground mines. At the more important points along the fifty miles of entrenchments field-works and redoubts for infantry and guns were built, most of them being armed with 4.7 or even 6 and 7.5 in. guns, which had been brought from Woolwich, Chatham, Portsmouth, and Devonport, and mounted on whatever carriages could be adapted or improvised for the occasion. [Illustration: The Lines of London] The preparation of the London lines was a stupendous undertaking, but the growing scarceness and dearness of provisions assisted in a degree, as no free rations were issued to any able-bodied man unless he went out to work at the fortifications. All workers were placed under military law. There were any number of willing workers who proffered their services in this time of peril. Thousands of men came forward asking to be enlisted and armed. The difficulty was to find enough weapons and ammunition for them, to say nothing of the question of uniform and equipment, which loomed very large indeed. The attitude of the Germans, as set forth in Von Kronhelm’s proclamations, precluded the employment of fighting men dressed in civilian garb, and their attitude was a perfectly natural and justifiable one by all the laws and customs of war.