We found a waterfall
twenty miles distant, where we built a power house, installed turbines
and dynamos and built an electric line to this place. We then erected a
machine shop, in which we placed our electric engines and air
compressors, and built a railroad connecting with the main line, and
after we had done that we started the tunnel. As you will observe, the
tunnel is a round bore twelve feet in diameter, and no explosives were
used in making it. We used a tunneling machine driven and operated by
compressed air, boring on the average fifty feet every twenty-four
hours, and we washed the debris away by a powerful stream of water
directed against the face of the tunnel so as not to obstruct the work.
We gave the tunnel for the first five miles a grade of one foot in ten
and from that point to the summit a grade of sixty degrees, and laid
heavy steel segment rails six feet apart bolted to the solid rock, by
this means dispensing with ties and permitting a free flow of water and
slum. We found it necessary to build a chamber within the mouth of the
tunnel sixty feet long, with automatic doors opening and shutting, to
secure an abundance of air in the tunnel, and also in the observatory.
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