What is "rectification of a globe"

Rectification \Rec`ti*fi*ca"tion\ (r?k`t?*f?*k?1sh?n), n. [Cf. F. rectification.]

1. The act or operation of rectifying; as, the rectification of an error; the rectification of spirits.

   After the rectification of his views, he was incapable of compromise with profounder shapes of error.
   --De Quincey.

2. (Geom.) The determination of a straight line whose length is equal a portion of a curve.

   Rectification of a globe (Astron.), its adjustment preparatory to the solution of a proposed problem.