Read it through once

AFTER a close study of the face of the pilot on watch, I was satisfied that I had never seen him before; so I went up there. The pilot inspected me; I re-inspected the pilot. These customary preliminaries over, I sat down on the high bench, and he faced about and went on with his work. Every detail of the pilot-house was familiar to me, with one exception,--a large-mouthed tube under the breast-board. I puzzled over that thing a considerable time; then gave up and asked what it was for.