The Journals of Lewis & Clark: Lewis, July 15, 1804
Lewis, July 15, 1804
Sunday July 15th This evening I discovered that my Chronometer had stoped, nor can I assign any cause for this accedent; she had been wound up the preceding noon as usual. This is the third instance in which this instrument has stopt in a similar manner since she nas been in my possession, tho the first only since our departure from the River Dubois. in the two preceding cases when she was again set in motion, and her rate of going determined by a series of equal altitudes of the sun taken for that purpose, it was found to be the same precisely as that mentioned in the preliminary remarks to these observations, or 15 s & 5 tenths too slow in 24 h-as her rate of going after stoping, and begin again set in motion has in two instances proved to be the same, I have concluded, that whatever this impediment may procede from, it is not caused by any material injury which her works have sustained, and that when she is in motion, her error on mean time above stated, may be depended on as accurate. In consequence of the chronometer's having thus accedentally stoped, I determined to come too at the first convenient place and make such observations as were necessary to ascertain her error, establish the Latitude & Longitude, and determine the variation of the nedle, in order to fix a second point of departure.