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.