sted Tom.

The orders were given, the tanks filled, the rudders set, and, with
hatches closed, the M. N. 1 submerged. Then, with the powerful
searchlight aglow, the search was begun. Moving along only a few feet
above the floor of the ocean, those in the submarine peered from the
glass windows for a sight of the sunken Pandora.

All the rest of that day they cruised about below the surface. Then
they moved in ever widening circles. Evening came, and the wreck had
not been found. The search was kept up all night, since darkness and
daylight were alike to those in the undersea craft.

But when three days had passed and the Pandora had not been seen, nor
any signs of her, there was a feeling of something like dismay.

"Where is it?" demanded Mr. Hardley. "I don't see why we haven't found
it! Where is that wreck?" and he looked sharply at Tom Swift.

CHAPTER XVIII

A SEPARATION

"Mr. Hardley," began Tom calmly, as he took a seat in the main cabin,
"when we started this search I told you that hunting for something on
the bottom of the sea was not like locating a building at the
intersection of two streets."

"Well, what if you did?" snapped the gold-seeker. "You're supposed to
do the navigating, not I! You said if I gave you the latitude and
longitude, down to seconds, as well as degrees and minutes, which I
have done, that you could bring your submarine to that exact point."

"I said that, and I have done it," declared Tom. "When we computed our
position the other day we were at the exact location you gave me as
being the spot where the Pandora foundered."

"Then why isn't she here?" demanded the unpleasant adventurer. "We
went down to the bottom at the exact spot, and we've been cruising
around it ever since, but there isn't a sign of the wreck. Why is it?"

"I'm trying to explain," replied Tom, endeavoring to keep his temper.
"As I said, finding a place on the open sea is not like going to the
intersection of two streets. There everything is in plain sight. But
here our vision is limited, even with my big searchlight. And being a
few feet out of the way, as one is bound to be in making nautical
calculations, makes a lot of difference. We may have been close to the
wreck, but may have missed it by a few yards."

"Then what's to be done?" asked Mr. Hardley.

"Keep on searching," Tom answered. "We have plenty of food and
supplies. I came out equipped for a long voyage, and I'm not
discouraged yet.