The late general 11. II. Sibley, and Indian agent Taliaferro, tes- 
tify to the pleasure with whicli they received and entertained 
Nicollet during the winter months, at Mendota and Fort Snelling. 
when his active explorations were suspended, and he was engaged 
in constructing his preliminary maj). -'In those days when the 
nearest settlement of whites was nearh' three hundred miles dis- 
tant, the advent of a decent and intelligent visitor was hailed 
with delight." 
Until 18HS Nicollet was thereafter engaged in mapping the 
region of the upper Mississippi. He was accompanied by ex- 
perienced Canadian frontiersmen, selected usually by the fur 
companies. (Chouteau & Co., of St. Louis.) and frerpiently from 
their own men. lie employed for the first time in this region 
those methods and principles which have been the basis of all the 
more recent surveys. The vastness of the area which he covered 
alone rendered it necessary to depend on more inaccurate methods 
for filling in the details between the points astronomically deter- 
mined. Wherever ]Mr. Nicollet went, he was indefatigable in the 
use of the telescope for ol)serving occultations and eclipses, and 
•of the sextant, with which he was very skillful. \\\\\\ these, a 
pocket chronometer, artiilcial horizon of mercury and l)arometer. 
he obtained astrom^mic and tojMjgraphic results, possessing re- 
markable accuracy for the means employed. Mi". Nicollet was 
the first explorer who made use of the barometer in ol)taining the 
elevation of our great interior country above the sea. An ab- 
stract of the methods and principles by which he was governed is 
given in his report, and these have sei'ved as a guide to many sub- 
sequent observers. 
'I'lic picliminarv map which he tlius constructcil extended on 
the east from the longitude of Madison in Wisconsin to the one 
hundiH'dth meridinn. and from tlie iiortlicrn international boundary 
to tile parallel of />S degrees and iJd miiintes. wliicli is just below 
the mouth of the ^lissouri river. it enil)raci'd not alone the ac- 
curate location of rivers and lakes, and the rejjresentation of the 
princijial topographic elevations. l)ut it showed many details of 
historic discovery and geograjjliy. and facts ri'specting the loca- 
tion of the Indian tribes, and the al)original names for streams 
and lakes. Nicollet familiarize(l himself witii early discovery, 
and i)articularly with the early Kreneli explorations, and it was 
one of his aims to resuscitate and reclaim for his countrymen tlie 
