STANHOPE AND TYNE RAILWAY.-Another opulent and persevering company have carried a railway from the river Tyne, at South Shields, in a north-west direction, forming an outlet to several collieries in its route, and also affording great facilities to the celebrated lime-works in the western part of this county-Durham. In consequence of the undulating surface, the western part of the line is worked on the self-acting inclined plane, and stationary engine principle. At Shields, there is an extensive quay completed, upon which are erected stone piers, to carry the several drops and the timber roadway, the trussed framing supporting the latter being a highly creditable specimen of constructive carpentry.

Upon the Hartlepool railway several extensive works have been completed. There were excavated from the great Crimdon cut, upwards of eight hundred thousand cubic yards of earth; its greatest depth is seventy feet; greatest width at the top, eighty yards, and nine yards in width at the formation level; the greatest part of it was deposited in the stupendous Hartlepool embankment, and the remainder of the latter formed with the earth excavated from the docks at Hartlepool. The residue of the above great cut was deposited in the adjoining Hesleton-dene embankment, of eightyfive feet in height, and the deficiency to form it obtained from the adjacent north-west cuttings. The Edderacres embankment, near Castle Eden, is seventy feet in height, and that at Pespool sixty feet. In consequence of the formation of this railroad, the small fishing town of Hartlepool has rapidly risen into importance, as a port of traffic and refuge.

We cannot close this retrospective view of the foregoing railroads already executed in the north, without a glance, however cursory, at that noble work of art, the Liverpool and Manchester railway, which clearly evinced the utility of such speculations, and accelerated the formation of the London and Birmingham, Grand Junction, Great Western, and other gigantic railroads, which are now of such national importance.

The distance between Liverpool and Manchester by the railroad is thirty-one miles. The great tunnel at the former place is one and a quarter miles in length, twenty-two feet wide, and sixteen feet in height; the side walls being five feet high, surmounted by a semicircular arch of eleven feet radius. Olive Mount excavation, near Liverpool, is seventy feet in depth, and two miles in length. The next object worthy of notice, is Parr Moss, where twenty-five feet of embankment have been required to form one of five feet high, owing to the imperfect foundation. The Sankey viaduct, nearly fourteen miles from Liverpool, contains nine arches, of fifty feet span each, the railroad upon it being elevated seventy feet above the valley; the structure is principally brick, having stone facings. We next arrive at the large Kenyon excavation, from which there were eight hundred thousand cube yards of earth removed. After passing three or four bridges, we enter the Chatt Moss level. This morass varies in depth from ten to forty feet, and comprises an area of nearly eight thousand On the eastern border it was with much difficulty that the embankment could be consolidated, but time, ingenuity, and perseverance finally became predominant. Throughout the line of rail

acres.

MANCHESTER AND LIVERPOOL RAILWAY. 39

road, there were excavated and removed, upwards of three millions of cubic yards of stone, clay, and other soils.

CHAPTER III.

GRADIENTS.

Of expressing the Rate of Inclinations-Rules for calculating the several parts of Inclined Planes-Estimated by Geometry-Tables of Gradients-Rule for ascertaining the proper Inclination, to equalise the Draught in each direction, for a Descending Trade-Examples shewing how to calculate by itRatio of Waggons of one-third, fourth, and fifth parts of the weights of the gross downward Load, explanatory of the Equalised Planes.

Without wishing to appear fastidious, it may be necessary to observe, that, when speaking of gradients, they are sometimes expressed as at a rate of one yard perpendicular to so many yards horizontal, or at a rate of one foot perpendicular to so many feet horizontal. But such extra explanations are quite superfluous, as it is generally understood when we say 1 in 100, 1 in 200, and so on, that the first number represents the perpendicular height, and the latter the horizontal length in attaining such height, and that both numbers are of the same denomination, as yards, feet, &c., unless expressly stated otherwise. We shall, therefore, throughout this work, omit specifying whether the inclinations are in feet, or any other measure.

It may be necessary to observe that the inclination of a plane; the sine of inclination; the height per mile, or the height for any length; and the ratio, &c., are all understood as synonymes.

Having the inclination, per foot, of a plane given to find the corresponding inclination per mile, chain, or yard; also to find the ratio of the plane.

1. Multiply the inclination per foot by 5280, (the number of feet contained in a mile) and the product will be the inclination per mile.

2.-Inclin. per ft.X66

3. Inclin. per ft.X3

inclin. per chain.

inclin. per yard.

4.-Divide 12 by the inclin. per foot, and the quotient will represent the ratio of the plane. If calculated decimally, annex as many cyphers to the 12 for a dividend as there are decimals contained in the divisor.

EXAMPLES.

1.-A plane ascending at the rate of in. per foot: then X5280580-330 in. or 27 ft. per ml.

By decimals of an in.=0625;

then 0625X5280-330' in., or 27.5 ft. per mile. 4.-Plane ascending of an inch per foot :*

6

then X192=64, ratio of the plane, 1 in 64. By decimals,

then 12.00001875-64, ratio of the plane 1 in 64.

The ascent, per yard, being given, to find the same ascent, per mile, per chain, or per foot; also, to find the ratio of the plane.

1:-Ascent per yardX1760=ascent per mile. 2.--Ascent per yard×22=ascent per chain. 3. Ascent per yard÷3=ascent per foot. 4.-Divide 36 (the number of inches contained in a yard) by the ascent per yard, and the quotient will be the ratio of the plane. If calculated decimally, annex cyphers as before.

The above 3-16ths of an inch, and the subsequent divisors, are inverted in order to divide fractionally.

G