Geographical Notices, 95 
Untrep States Survey or THE Cotorapo River.— A let- 
ter from one of Lieut. Ives’s oe , now engaged in the survey. 
of the Colorado River gives the following particulars in respect 
to the Expedition. 
“T.ieut, Ives has carried a minute hydrographic survey from 
the mouth of the Colorado to the mouth of the Rio Virgen, 
where the road to Salt Lake City approaches nearest the river. — 
We are now descending the river to meet the mule train and to 
commence the survey of the upper Colorado, Virgen, ete., with 
the land party. 
Our explorations have demonstrated the fact of the naviga- 
bility of ty Colorado to the mouth of the Virgen, a point far 
above that ever reached by any other exploring party—and the 
much-talked-of and much-dreaded ‘Big Cafion’ has been passed 
through in safety. Although the navigation of the river became 
more difficult as we approached within 60 or 70 miles of the 
mouth of the Virgen, we encountered no insurmountable obsta- 
cles even at this unprecedently low stage of the water, and there 
is now no question that with the quantity of water which flows- 
in its channel during most of the year, and with steamers adap 
to its navigation, the Colorado will afford the most feasible route 
for transportation of men and supplies to the region around 
Salt Lake. We hope to finish our land survey in three months.” 
MEXI 
. n Cc ‘ 1e joint — 
mmission, the astronomical work, barometrical levels, meteor- 
co 
ological record and magnetic observations. The second part 
hird 
—— the general botanical features of the country by Dr. John 
orrey described from memoirs of the assistants a 
Sayre themselves, and a separate description of the Cactacew by 
. George Engelmann of St. Louis. ‘he fourth part embraces 
the natural history of the country by . Spencer F. Baird 
based upon the notes of : em- 
a fies eehcame tows | iblighed contains a general map on a scale 
of 1: 6,000,000, Sed aici aecteinl naps of the boundary line 
and adjacent territory on a scale of 1: 600,000—are hereafter to 
be given D.C. 
Yale College Library, June 7, 1858. 
i 
ag. 
