) |
| | |
| | |
Exploration drift |A and B |Intermediate shaft. |
| | (West of shaft.) |
| | |
Twin tunnel. Enlargement |A and B | West shaft. |
of exploration drift | | (East of shaft.) |
=============================+========+=====================
======================================================================
4 | 5 | 6 | 7 |
----------------------------------+--------+------------+------------+
| | Length | Average |
DATES. | Time | tunnel | advance |
----------------------------------|elapsed,| excavated, | per day, |
| | in | in | in |
From | To | days. |linear feet.|linear feet.|
----------------------------------+--------+------------+------------+
Feb. 28, 1906. |May 12, 1906. | 74 | 346 | 4.7 |
| | | | |
Feb. 28, 1906.
Pages:
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41