BLIND a.
ry eyes. -- Blind spot (Anat.), the point in the retina of the eye where the optic nerve enters, and which is insensible to light. -- Blind tooling, in bookbinding and leather work, the indented impression of heated tools, without gilding; -- called also blank tooling, and blind blocking. -- Blind wall, a wall witho…
BLOCK SYSTEM n.
un 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 permissive blocking.…
BLUE a.
curial ointment. -- Blue Peter (British Marine), a blue flag with a white square in the center, used as a signal for sailing, to recall boats, etc. It is a corruption of blue repeater, one of the British signal flags. -- Blue pill. (Med.) (a) A pill of prepared mercury, used as an aperient, etc. (b) Blue mass. -- Bl…