the shaft.

Full-sized twin tunnel A and B Intermediate shaft.
(East of shaft.) Apr. 4, 1906. Oct. 31, 1906. 210 783 3.7 Top center heading and bench. Muck loaded by
steam shovel. Working alternately in headings
east and west of the shaft. Full-sized twin tunnel A and B Intermediate shaft.
(East of shaft.) Nov. 1, 1906. Dec. 26, 1906. 56 311 5.5 Top full-width heading and bench. Muck loaded
by steam shovel working exclusively on this
heading. Exploration drift A and B Intermediate shaft.
(West of shaft.) Mar. 1, 1907. July 23, 1907. 145 947 6.5 Exploration drift about 9 ft. by 12 ft. Mucking
by hand. Fourteen timber bents were placed in
March, and seven in April, 1907. Twin tunnel. Enlargement
of exploration drift A and B West shaft.
(East of shaft.) Sept. 6, 1907. Dec. 4, 1907. 89 603 6.8 Drift excavated to full width and bench. Muck
loaded by steam shovel.

Thirty-Second Street.

Type of excavation.	Tunnels.	Worked from:	Dates.		Time elapsed, in days.	Length of tunnel excavated, in linear feet.	Average advance per day, in linear feet.	Methods and conditions.
			From	To
Full-sized single tunnel	C	1st Ave. shaft.	Jan. 25, 1906.	Apr. 30, 1906.	95	367	3.9	Top heading and bench. Muck loaded by hand.
Full-sized single tunnel	D	1st Ave. shaft.	Jan. 27, 1906.	Apr. 30, 1906.	93	354	3.8	"         "        "       "           "        "      "     "
Full-sized twin tunnel	C and D	1st Ave. shaft.	May 22, 1906. Aug. 11, 1906.	July 24, 1906.[E] Nov. 29, 1906.	173	810	4.7	Double heading and bench. Muck loaded by steam shovel. Stretches aggregating 200 ft. narrowed to about 25 ft. and later enlarged are included.
Narrowed twin tunnel	C	Intermediate shaft.	Mar. 19, 1906.	May 28, 1906.	70	58	0.8	Excavation about 30 ft. wide. Top full-width heading and bench. Muck loaded by hand. Steam shovel not installed.
Full-sized twin tunnel	C	Intermediate shaft. (East of shaft.)	May 29, 1906. July 18, 1906. Aug. 12, 1906. Jan. 15, 1907. Feb. 17, 1907.	July 3, 1906[E] July 31, 1906. Nov. 23, 1906. Feb. 5, 1907. Mar. 21, 1907.	208	1,206	5.8	Excavation about 30 to 35 ft. wide. Top full-width heading and bench. Muck loaded by steam shovel.
Full-sized twin tunnel	C and D	Intermediate shaft. (West of shaft.)	Dec. 1, 1905.	May 10, 1906.	161	225	1.4	Double heading and bench. Part of the muck handled by hand and part by steam shovel.
Exploration drift	C and D	Intermediate shaft. (West of shaft.)	Feb. 1, 1907.	Sept. 13, 1907.	225	1,033	4.6	Exploration drift about 10 ft. by 13 in. Muck loaded by hand. 14 ft. timbered.
Twin tunnel. Enlargement of exploration drift	C and D	Eastward from open cut.	Feb. 1, 1908.	Feb. 14, 1908.	14	65	4.6	At portal of twin tunnels. Drift excavated to full width and bench. Muck loaded by hand. 12 ft. timbered.
Twin tunnel. Enlargement of exploration drift	C and D	Eastward from open cut.	Feb. 15, 1908.	Apr. 14, 1908.	59	524	8.9	Drift excavated to full width and bench. Muck loaded by steam shovel. Full-width tunnel timbered for 26 ft. independently of the main excavation.