"Air," explained Mercer. "There are two other tanks inside the globular body. That shape was adopted, by the way, because a globe can withstand more pressure than any other shape. And we may have to go where pressures are high."
"And so," I said, "we don these things and stroll out into the Atlantic looking for the girl and her friends?"
"Hardly. They're not quite the apparel for so long a stroll. You haven't seen all the marvels yet. Come along!"
e led the way through the patio, beside the pool in which our strange visitor from the depths had lived during her brief stay with us, and out into the open again. As we neared the sea, I became aware, for the first time, of a faint, muffled hammering sound, and I glanced at Mercer inquiringly.
"Just a second," he smiled. "Then—there she is, Taylor!"
I stood still and stared. In a little cove, cradled in a cunning, spidery structure of wood, a submarine rested upon the ways.
"Good Lord!" I exclaimed. "You're going into this right, Mercer!"
"Yes. Because I think it's immensely worth while. But come along and let me show you the Santa Maria—named after the flagship of Columbus' little fleet. Come on!"