BOOK II. THE SIEGE OF LONDON. CHAPTER I. THE LINES OF LONDON. The German successes were continued in the North and Midlands, and notwithstanding the gallant defence of Sir George Woolmer before Manchester and Sir Henry Hibbard before Birmingham, both cities were captured and occupied by the enemy after terrible losses. London, however, was the chief objective of Von Kronhelm, and towards the Metropolis he now turned his attention. 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 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.