Page:In defense of Harriet Shelley, and other essays.djvu/310

 MARK TWAIN

go to work to beat it, a sailor came in and pulled out the &quot;Empty&quot; end of the first slat and put it back with its reverse side to the front, marked &quot;Full.&quot; He made some other change, I did not notice what. The slat-frame was soon explained. Its function was to indicate how the ballast in the ship was dis tributed. The striking thing was that the ballast was water. I did not know that a ship had ever been ballasted with water. I had merely read, some time or other, that such an experiment was to be tried. But that is the modern way; between the experimental trial of a new thing and its adoption, there is no wasted time, if the trial proves its value.

On the wall, near the slat-frame, there was an outline drawing of the ship, and this betrayed the fact that this vessel has twenty-two considerable lakes of water in her. These lakes are in her bottom ; they are imprisoned between her real bottom and a false bottom. They are separated from each other, thwart ships, by water-tight bulkheads, and separated down the middle by a bulkhead running from the bow four-fifths of the way to the stern. It is a chain of lakes four hundred feet long and from five to seven feet deep. Fourteen of the lakes contain fresh water brought from shore, and the aggregate weight of it is four hundred tons. The rest of the lakes contain salt-water six hundred and eighteen tons. Upward of a thousand tons of water, altogether.

Think how handy this ballast is. The ship leaves port with the lakes all full. As she lightens forward through consumption of coal, she loses trim her head rises, her stern sinks down. Then they spill

�� �