BLOCK SYSTEM n.
s, and trains are so run by the guidance of electric, or combined electric and pneumatic, signals that no train enters a section or block until the preceding train has left it, as in absolute blocking, or that a train may be allowed to follow another into a block as long as it proceeds with excessive caution, as in per…
BONE v.
To sight along an object or set of objects, to see if it or they be level or in line, as in carpentry, masonry, and surveying. Knight. Joiners, etc., bone their work with two straight edges. W. M. Buchanan.