in the Indian and his wife expressed their gratitude, and Tom, after
letting the little brown baby cling to his finger, and patting its
chubby cheek, went on his way with Koku.

"Well, that was some excitement," mused Tom, who made little of the
shot itself, for the condor was such a mark that he would have had to
aim very badly indeed to miss it. And perhaps only the electric rifle
could have killed quickly enough to prevent the baby's being injured in
some way by the big bird, even though it was dying.

"Master heap good shot!" exclaimed Koku, admiringly.

The tunnel work went on, though not so well as when Tom's explosive was
first used. The rock was indeed getting harder and was not so easily
shattered. Tom made tests of the pieces he had obtained from the
outcropping ledge on the mountain where he had shot the condor, and
decided to make a change in the powder.

Shipments were regularly received from Shopton, Mr. Swift keeping
things in progress there. Mr. Damon's business was going on
satisfactorily, and he lent what aid he could to Tom. As for Professor
Bumper he kept on with his search for the lost city of Pelone, but with
no success.

The scientist wanted Tom and Mr. Damon to go on another trip with him,
this time to a distant sierra, or fertile valley, where it was reported
a race of Indians lived, different from others in that region.

"It may be that they are descendants from the Pelonians," suggested the
professor. Tom was too busy to go, but Mr. Damon went. The expedition
had all sorts of trouble, losing its way and getting into a swamp from
which escape was not easy. Then, too, the strange Indians proved
hostile, and the professor and his party could not get nearer than the
boundaries of the valley.

"But the difficulties and the hostile attitude of these natives only
makes me surer that I am on the right track," said Mr. Bumper. "I shall
try again."

Tom was busy over a problem in explosives one day when he saw Tim
Sullivan hurrying into the office of the two brothers. The Irishman
seemed excited.

"I hope there hasn't been another premature blast," mused Tom. "But if
there had been I think I'd have heard it."

He hastened out to see Job and Walter Titus in excited conversation
with Tim.

"They didn't come out, an' thot's all there is to it," the foreman was
saying. "I sint thim in mesilf, and they worked until it was time t'
set off th' blast. I wint t' get th' fuse, an' I was goin' t' se