Referring to the profile in that number of the SCIENTIFIC AMERICAN, the
following are the distances to the various points where the work is
being prosecuted:
Distance from east end to central shaft 12,837.294 feet
" " central shaft to west shaft 9,747.072 "
" " west shaft to new shaft 265.000 "
" " new shaft to well No. 4 659.150 "
" " well No. 4 to pier[1] 1,522.825 "
----------
" " east end to pier[1] 25,031.341 "
[Footnote 1: The instrument pier is 4 feet west of the present west end
of the tunnel.]
The following are the lengths of the headings at the various points of
the work, Dec. 2, 1867:
Length of east end heading 4,608.000 feet
" " west shaft, east heading 1,262.000 "
" " " " west heading 611.000 "
" " west end heading 617.000 "
----------
Total length of headings 7,098.
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