It has been beneath the surface of our country that these and many other difficulties of vast magnitude--unknown to and unthought of by the multitude--have for many generations been successfully encountered by science, capital, and by almost superhuman physical exertion; and it was accordingly, as we have stated, from beneath the surface of Great Britain that an organised corps of civil engineers, who, like those we have named, had regularly served as apprentices, arose, in the emergency of a moment, to assist their eminent brother engineers above ground, in constructing for the country the innumerable railways so suddenly required. CHAPTER II. ON THE MAINTENANCE OF THE PERMANENT WAY. As soon as an infant railway can run alone--we mean as soon as its works are all constructed, its permanent way finished, its buildings executed, its locomotive engines as well as its carriages constructed, and its whole establishment of officers and men appointed and organised--the chief engineer, like a month-nurse, usually departs to new troubles, leaving the maintenance of the way to those of his assistants whom he considers, and who in the opinion of the Directors of the Company are deemed, the most competent to execute its various details. The manner in which this important duty is performed on the London and North-Western Railway is very briefly as follows:-- The line is, according to the nature of its works, divided into distances of from 17 to 30 miles, to each of which there is appointed “_an overlooker_,” whose district is subdivided into “lengths” of one or two miles, to each of which is appointed “_a foreman_,” with his gang of two or three men. Every morning before the first train passes, the foreman is required to walk over his length, not only generally to inspect it, but especially to ascertain that each of the wooden keys which secure the rails are firmly fixed; and in case of any deficiency, his first operation is to put up, 800 yards above the point, a signal flag, which flies until the necessary repair is executed. The ambition of the superintendent of the division is, however, to execute all necessary repairs not only with the utmost promptitude and despatch, but, if possible, without impeding the passage of the public; and considering the number of up and down passenger, goods, and coal trains (vide ‘Bradshaw’s List’) that are continually passing along the line, the success with which this object can, in railway management, be practically attained is worthy of explanation. For instance-- 1. In February, 1848, three miles of single rails were relaid by the Company’s engineer in Kilsby Tunnel; 125 men and one ballast-engine being employed in this work for four weeks, without stopping the public.