Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1849 edition. Excerpt: ... a degree of firmness proportionate to the distance its carriages were placed apart. If a cranked axle be supported by carriages situated near its centre, and impelled by forces acting in contrary directions, as those transmitted to it from the cylinders, it would cease to be perpendicular to the movement of the pistons, upon the carriages becoming the least worn, and would form an angle proportionably large, accordingly as the carriages were placed near the centre. The flanges surrounding the wheels would therefore knock against the rails, and the engine undergo violent lateral movements from its direct course, which would be dangerous, on account of the great velocity. A like effect occurs when the cranks are placed at the extremities of the axle, instead of near the middle of it, as in the case of engines having the cylinders placed on the outside. The wear of the carriages, also, has the effect of increasing the force of the lateral movements considerably. 15. Of Locomotives employed in conveying Goods.--It is customary, in the conveyance of goods, to employ engines with their driving-wheels coupled to the fore ones, which is effected by connecting rods; in which case the fore-wheels are of equal diameter with the driving-wheels. This coupling possesses no other advantage than that of increasing the power of adhesion, by allowing the fore-wheels to partake of the weight carried by the others. The weight supported by the wheels of the engines employed on the Liverpool and Manchester Railway is generally about five tons; and taking one-fifth of this weight as the maximum amount of adhesion, would be sufficient to propel 250 tons on a level; but the minimum amount of adhesion being no more than one-fifteenth, the engines would not be...
