Note 84 — PART III. LOCAL DESCRIPTION OF THE WORKS.

The cramps seem to have been of various kinds. Some authors speak of iron cramps. One antiquary, I know, spent a livelong summer’s day knee-deep in the water, extracting one which proved to be entirely of lead. A. cramp, of very curious form and structure, taken from this bridge, is preserved in the museum at Chesters, and is figured Plate VII. fig. 1.; it seems to have been triply dove-tailed; the substance of it is iron, but it has been coated all over to the thickness of one-eighth of an inch with lead. The iron would give the instrument tenacity, and the lead protect the more corrosive metal from oxidization; truly the Romans built for perpetuity.