Levelage

Since connection was made by levelage with German main shaft, a large body of ore has been opened which is being backstoped.^([sic])

Source: wiktionary

The entire group can be worked by a system of levelage and cross-cuts from the workings of the main shaft on the Columbia Avenue.

Source: wiktionary

The most advanced socialist could not have desired a more perfect system of levelage.

Source: wiktionary

The surface of Lake Erie has generally been considered as five hundred and sixty-four feet above tide-water at Albany; see the Report of Michigan, 1839-40. The topographer of that State, S.W. Higgins, Esq., puts it at 565, 333 feet. If this last number represents the levelage of the Erie Canal, it is probably good for the surface of the Lake, as it was when the surveys were made for that work, twenty-five years since.

Source: wiktionary