Mr. NICHOLAS WOOD'S Practical Treatise on Railroads, is a compendium
of the statistics of internal communication ; the pur- pose of which is to establish the superiority, in cheapness as well as speed and efficiency, of railway conveyance to turnpike-roads and canals. This is done by scientific calculations of the relative cost and quantity of work done—by tables of power and resistance, friction and speed—and a careful enumeration and minute com- parison of the advantages and drawbacks attendant on each mode. The view of the progress of railways, from the first colliery trains of timber to the gigantic undertakings now in progress, is full of interest: and it is curious to observe that the latest and newest principle of construction is but an improvement on the first rude plan. The Great Western Railway is the only one that materially differs from the rest, all of which resemble each other in their leading features : and the mode ad, ptcd by Mr. BRUNEL, of laying down the rails on wooden sleepers secured by cross-pieces, form- ing a strong framework of timber resting on the soil, is similar to that of the majority of American railways; the addition of piles to preserve the evenness and solidity of the road constitutes the main difference. These piles are driven, at intervals of fifteen feet, several feet into the subsoil, for the purpose of holding down the wooden rails, so that they may resist the upward strain of gravel beaten in underneath them until they are slightly curved ; after which, their upper surface is planed down to a uniform level. The upward pressure which the piles have to resist is estimated at a ton to each fcot of rail ; and the object of it is to counteract the effect of the weight of the carriage-wheels, which, being eight and in some cases ten feet in diameter, are immensely heavy. The result remains to be seen : whether the inequalities we have heard complained of arise front an imperfect consolidation of the soil, or the insufficiency of the piles to preserve the level of the rails, we do not know. Notwithstanding present appearances, it would be premature to decide against the ultimate SUCCCSS of the experiment in this early stage of the undertaking. Mr. Woon's work includes a tabular statement of the ex- penses and proceeds of the Manchester and Liverpool Railway, up to last midsummer,—most useful data for other calculations ; and that portion devoted to the subject of motive power is enriched by much valuable information (rem M. PAMBOUR'S treatise on Locomotive Engines. The volume is illustrated by engraved plans and sections of the several railways and various engines ; and it altogether combines a great mass of matter on a subject of paramount importance, which can never be too completely eluci- dated.
Previous page
