The North Bridge, a fine iron structure, spans the valley, giving connexion between the opposite higher parts of the town.
A fine railway bridge (1888) spans the Ohio.
But the mere paying out of sufficient slack is not a guarantee that the cable will always lie closely along the bottom or be free from spans.
The advantage claimed for roofs formed with one or two large spans is that they permit the platforms and tracks to be readily rearranged at any time as required, whereas this is difficult with the other type, especially since the British Board of Trade requires the pillars to be not less than 6 ft.
