Assertion: pike | /r/CapableOf | take celestial observations
Facets:
value: to determine its latitude
type: PURPOSE
Source sentences:
text: On a short side trip (February 12 to 14), Pike traveled to the North West Company fur post on Upper Red Cedar Lake (now commonly known as Cass Lake), erroneously designating the lake as the ultimate source of the Mississippi, and taking celestial observations to determine its latitude.