32

of equal area, to one of the proposedcables * at the points of suspension, andthe props may be 20 feet lower; andthough at the points of suspension theascent is 1 perpendicular to 8 ascending,the average will be 1 to nearly 16. In thenew road from Shrewsbury to Holyhead,improved under the direction of the par-liamentary commissioners, where “ to thesuperior science” exhibited, the Select Com-mittee of the House of Commons say intheir Report “ high praise is due,” the ascentfor a length of 600 feet is 1 to 17. (Seepage 55, Report, Highways of the King-dom, 25th June, 1819, and page 9., 18thJuly, 1820.)

The excess of the cost (70,000/.) of thebridge recommended by the Committee ofthe House of Commons above that (34,600/.)recommended by the author, arises, 1st, be-cause there are not in the latter any sus-

* To determine the height of the props above theapex of the curve, see the table at 7°«10', then

as Tab. y : Tab. ar. :: 280 : X 280 = 17.5726 =

a Tab. y

the absciss of the curve.