"I think I could," said Ralph, rather doubtingly, it must be admitted.
"Then I'll give you a little hint, if you'd like to try to make an investigation," said the captain. "Directly forward of the table, which contains the chart, and below the three levers, you will see a glass column with red colored liquid in it,——"
"I know what you mean now," said Ralph, interrupting.
"Well, simply get the number on the card on the right side of the glass column. Do you understand?" remarked the captain.
"Yes; but why not take the numbers on the left side also?" asked Ralph.
"They merely indicate the pressure. Depth below the surface is all we want," rejoined the captain.
"Well, here goes; and I hope they won't catch me at it," said Ralph, as he slowly moved out.
"One moment," said the captain, as he put forth a restraining hand. "What will you do, or how will you act if some one should catch you in the tower?" he asked.
Ralph hesitated: "I hadn't thought of that; why,—well,—I suppose I should try to explain it in some way or other," he said.
"I am afraid that would not do. Allow me to make a suggestion. Go up boldly, as though you had a perfect right to, or that you did not suspect it was a forbidden place; if some one accosts you look at him in a surprised way, make an apology, and retire; I give you this pointer because you may be flustrated and unable to make a prompt reply, and that would show guilt of some kind," said the captain.