The digger lay on his stomach, dug ahead of him, threw the 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.