What is "upcast shaft"

Upcast \Up"cast`\, n.

1. (Bowling) A cast; a throw.
   --Shak.

2. (Mining.) The ventilating shaft of a mine out of which the air passes after having circulated through the mine; -- distinguished from the downcast. Called also upcast pit, and upcast shaft.

3. An upset, as from a carriage. [Scot.]

4. A taunt; a reproach. [Scot.]
   --Sir W. Scott.