From this tank the water is pumped out for use.

Into one of these tanks the unfortunate slave was placed, and confined by one of his ancles to the bottom of it; and the water was suffered to flow in from above.

He was compelled to pump out the water as fast as it came in, by means of a long rod or handle connected with the pump above ground.

He was not allowed to begin until the water had risen to his middle.

Any pause or delay after this, from weakness and exhaustion, would have been fatal, as the water would have risen above his head.