Captain Weston, taking a noon observation, announced:
"Well, we're here!"
"Do you mean at the wreck?" asked Mr. Swift eagerly.
"We're at the place where she is supposed to lie, in about two miles of water," replied the captain. "We are quite a distance off the coast of Uruguay, about opposite the harbor of Rio de La Plata. From now on we shall have to nose about under water, and trust to luck."
With her air tanks filled to their capacity, and Tom having seen that the oxygen machine and other apparatus was in perfect working order, the submarine was sent below on her search. Though they were in the neighborhood of the wreck, the adventurers might still have to do considerable searching before locating it. Lower and lower they sank into the depths of the sea, down and down, until they were deeper than they had ever gone before. The pressure was tremendous, but the steel sides of the Advance withstood it.
Then began a search that lasted nearly a week. Back and forth they cruised, around in great circles, with the powerful searchlight focused to disclose the sunken treasure ship. Once Tom, who was observing the path of light in the depths from the conning tower, thought he had seen the
