What is "night-glass"

Usage examples of "night-glass".

In this chair, wrapped in his cloak, he spent the long moonlit night, rising at every bell to walk along the gangway to the forecastle and out along the bowsprit to peer at the Spartan with his night-glass between the spritsail course and its topsail.

I legged off through the dew no comfortabler for knowing that a night-glass surely watched me go.

I pulled myself to my feet and climbed the companionway to the bridge, where the captain, peering through a pair of night-glasses, was rapping out orders through an electrical loud-hailer which amplified his clicking, harshly accented speech (it was an Ivory Coast dialect with which I was unfamiliar).