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whole, gives about 8,(109 lbs. for the total weightwhich the cables bore.

This bridge was used experimentally, to in-struct the pontoneers; but never applied in theoperations of the army.

In 1820 a bridge on this principle was thrownacross the Scarpe, near I)ouay, by CaptainRobert; and a committee of artillery officers re-ported favourably of the construction. The ap-paratus sufficient for a river 120 feet wide, waseasily transported on two carriages, the totalweight being about (1,097 lbs.

The floor was formed of (1 cables, fastened to,and stretched by means of frames, laid hori-zontally on each side of the river, behind pilessunk as deep as possible in the ground. A ver-tical frame, forming a potence, or gallows, wasfixed upon each of the horizontal frames, with2 iron rollers on the summits, over which the 2suspension cables were passed, and adjusted toproper tension, by capstans. Tackles werefastened to the suspension cables, at (1 feet dis-tance, to combine, as before, the suspensioncables with the floor cables. This bridge borean eight pounder limbered up, and 10 men.

The ropes which supported the floor, appear,in this case, to have been braced togetherdiagonally, by 2 strong ropes, crossed several