What is "uncasing"

Usage examples of "uncasing".

Again uncasing his precious, irreplaceable binoculars, he fixed them on that area, and what he saw brought his breath hissing between his suddenly clenched teeth.

Peter was obliged to reply, and deliberately uncasing his eyes and blowing his nose, he was on the point of opening his mouth, as John came into the room, and threw himself into a chair with an air of great vexation.