76 EXPLORATIONS FROM A. D. 1852 TO A. D. 1857. 
fork of Humboldt’s river. The exploration was continued westward by a devious route through 
the mountains south of the Humboldt river to its valley at Lassen’s Meadows. Leaving the 
river, they then explored westward to the southern portion of the valley of Mud lakes. Pro- 
ceeding thence northwest, they crossed the eastern chain of the Sierra Nevada by the Madelin 
Pass, and followed Pit river to the mouth of Fall river. Here, leaving Pit river, Lieut. Beck- 
with travelled by the Old Emigrant road, southward along the elevated plateau between the 
two chains of the Sierra Nevada, to the Noble Pass road, which he followed through the 
eastern chain of the Sierra, near Susan's river, to Honey lake. Having connected his 
recent reconnaissance with the former line near the point where Smoky creek enters Honey 
Lake valley, Lieut. Beckwith retraced his steps by the Noble's Pass road, through the eastern 
chain of the Sierra Nevada to the summit plateau. Thence he followed the continuation of the 
same road through Noble's Pass, in the western chain of the Sierra, to Fort Reading, in the 
Sacramento valley. Much confusion in ideas, as well as in nomenclature, has arisen from the 
name ''Noble's Pass" being applied indiscriminately to two passes, (as well as to the road be- 
tween them,) one through the eastern, and the other through the western chain of the Sierra 
Nevada 
Leaving Fort Reading on July 15, Lieut. Beckwith ascended the Sacramento to Pit river, 
which he followed to within a few miles of the mouth of Fall river, thus nearly connecting with 
his former reconnaissance. Turning southward, he then followed Canoe creek to Noble's West- 
ern Pass, and thence by the road to Fort Reading, at which point the exploration terminated. 
AN EXAMINATION TO ASCERTAIN THE MOST PRACTICABLE LOCATION FOR A WAGON ROAD ALONG 
THE CARSON VALLEY ROUTE, PASSING NEAR LAKE BIGLER, (CALLED BY FRÉMONT, IN HIS MAP 
OF HIS SECOND EXPEDITION, ‘‘MOUNTAIN LAKE," AND ON HIS MAP OF THE THIRD EXPEDITION 
LAKE BONAPLAND.) 
This examination throws much light on the subject of the practicability of the route for a 
railroad. 
The altitudes were determined by an aneroid barometer. The determination of the eastern 
boundary of California was another object in the examination, and for this purpose the party 
used an astronomical transit and sextant with chronometers.. The report of these operations, 
by George H. Goddard, accompanies the annual report of the surveyor general of the State of 
California. Assembly document No. 5, session of 1856. 
SURVEY FOR A RAILROAD ROUTE TO THE PACIFIC, NEAR THE THIRTY-FIFTH PARALLEL, BY CAPTAIN A. 
W. WHIPPLE, TOPOGRAPHICAL ENGINEERS. 
The final report of Captain Whipple forms Volumes III and IV of the quarto edition of the 
Pacific Railroad Reports, Senate Ex. Doc. No. 18; House Ex. Doc. No. 91, 2d sess. 33d Cong. 
It is accompanied by a topographical | map in two sheets, drawn on a scale of 15 miles to 
an inch, and a sheet of profiles on a horizontal scale of 15 miles to an inch, and a vertical 50 
times the horizontal. There are, besides, geological maps and numerous other illustrations. 
His preliminary report forms part of House Doc. No. 129, 1st sess. 33d Cong. This edition 
is accompanied by a map in two sheets, and on scale of 1 to 900,000, and a profile of the route 
on a horizontal scale of 1 inch to 79,500 feet, and a vertical scale of 1 inch to 3,000 feet. 
Captain Whipple was assisted by Lieutenant J. C. Ives, Topographical Engineers; Dr J. M. 
Bigelow, surgeon and botanist; Jules Marcou, geologist and mining engineer; Dr. C. B. R. Ken- 
nerley, physician and naturalist; A. H. Campbell, principal assistant ‘railroad engineer; H. B. 
