f this is done
it will mean that the products of Peru--quinine bark, coffee, cocoa,
sugar, rubber, incense and gold can more easily be transported. But to
connect the two railroad lines a big tunnel must be constructed.

"My brother and I make a specialty of such work, and when we saw bids
advertised for, our firm put in an estimate. There was some trouble
with a rival firm, which also bid, but we secured the contract, and
bound ourselves to have the tunnel finished within a certain time, or
forfeit a large sum.

"That was over a year ago. Since then our men, aided by the native
Indians of Peru, have been tunneling the mountain, until, about a month
back, we struck a snag."

"What sort of snag?" Tom asked.

"A snag in the shape of extra hard rock," replied the tunnel
contractor. "Briefly, Paleozoic rocks make up the eastern part of the
Andean Mountains in Peru, while the western range is formed of Mesozoic
beds, volcanic ashes and lava of comparatively recent date. Near the
coast the lower hills are composed of crystalline rocks, syenite and
granite, with, here and there, a strata of sandstone or limestone.
These are, undoubtedly, relics of the lower Cretaceous age, and we, or
rather, my brother, states that he has found them covered with marine
Tertiary deposits.

"Now this Mesozoic band varies greatly. Porphyritic tuffs and massive
limestone compose the western chain of the Andes above Lima, while in
the Oroya Valley we find carbonaceous sandstones. Some of the tuffs may
be of the Jurassic age, though the Cretaceous period is also largely
represented.

"Now while these different masses of rock formation offer hard enough
problems to the tunnel digger, still we are more or less prepared to
meet them, and we figured on a certain percentage of them. Up to the
present time we have met with just about what we expected, but what we
did not expect was something we came upon when the tunnel had been
driven three miles into the mountain."

"What did you find?" asked Tom, who knew enough about geology to
understand the terms used. Mr. Damon did not, however, and when Mr.
Titus rolled off some of the technical words, the drug investor softly
murmured such expressions as

"Bless my thermometer! Bless my porous plaster!"

"We found," resumed Mr. Titus, "after we had bored for a considerable
distance into the mountain, a mass of volcanic rock which is so hard
that our best diamond drills are dulled in a short time, and