dirt under him, and worked it back with his feet till the man behind him,
also lying on his stomach, could catch it and work it back to the next.
As the tunnel lengthened the number of men behind each other in this way
had to be increased, so that in a tunnel seventy-five feet long there
would be from eight to ten men lying one behind the other. When the dirt
was pushed back to the mouth of the tunnel it was taken up in improvised
bags, made by tying up the bottoms of pantaloon legs, carried to the
Swamp, and emptied. The work in the tunnel was very exhausting, and the
digger had to be relieved every half-hour.

The greatest trouble was to carry the tunnel forward in a straight line.
As nearly everybody dug most of the time with the right hand, there was
an almost irresistible tendency to make the course veer to the left. The
first tunnel I was connected with was a ludicrous illustration of this.
About twenty of us had devoted our nights for over a week to the
prolongation of a burrow. We had not yet reached the Stockade, which
astonished us, as measurement with a string showed that we had gone
nearly twice the distance necessary for the purpose. The thing was
inexplicable, and we ceased operations to consider the matter. The next
day a man walking by a tent some little distance from the one in which
the hole began, was badly startled by the ground giving way under his
feet, and his sinking nearly to his waist in a hole. It was very
singular, but after wondering over the matter for some hours, there came
a glimmer of suspicion that it might be, in some way, connected with the
missing end of our tunnel. One of us started through on an exploring
expedition, and confirmed the suspicions by coming out where the man had
broken through. Our tunnel was shaped like a horse shoe, and the
beginning and end were not fifteen feet apart. After that we practised
digging with our left hand, and made certain compensations for the
tendency to the sinister side.