From this view o f the time-keeper it appears, that, fo r
near two years, it altered its rate very inconfiderably, and
therefore, that its error, according to the Greenwich rate,
i f w e had had no opportunities o f correcting it, would have
amounted only to s|°. T h a t afterward, at K in g George’s
Sound, or Nootka, it was found to have varied exceedingly
o f courfe, the longitude, b y its Greenwich rate, was becoming
confiderably erroneous. About this time, it Ihould
be remarked, the thermometer was varyin g from 65° to 41°.
The greateft alteration we ever obferved in the watch was,
during the three weeks w e were c ru izin g to the North ? in
w h ich interval, it gave the longitude o f the Eaft Cape w ith
a difference o f twenty-eight miles. I have marked the
longitude o f Saint Peter and Saint Paul, as given by the
time-keeper, notwithftanding it flopped a few days before
we arrived there ; this I was enabled to do, from comparin
g the longitude it gave the day before it flopped, w ith
that giv en b y Mr. Bayley’s watch, and a llow ing fo r the
error o f the latter.
T h e ufe o f fo accurate a meafure o f time is fufficiently
evident, from its furnifhing in itfe lf the means o f approximating
to the longitude at fea, as may be feen in the above
table. But, befides this, w e were enabled, b y the fame
means, to give a degree o f accuracy to the lunar obferva-
tions, which they cannot otherwife pretend to; and, at the
fame time, by reducing a number o f thofe obfervations to
one time, obtain refults approaching ftill nearer the troth.
In furveying coafts, and afcertaining the true pofitions o f
capes and head-lands, it reaches the utmoft degree o f practical
exadlnefs. On the other hand, it is to be obferved, that
lunar obfervations, in their turn, are abfolutely neceflary, in
order to reap the greateft poflible advantages from the timekeeper
;
keeper; fince, by afcertaining the true longitude o f places,
they difcover the error o f its rate. The original obfervations,
that were made in the courfe o f this voyage, have
been publifhed by order o f the board o f longitude, and to
thofe I mud refer the reader, for his further information on
this fubjedt.
N . B . The obfervatories were placed on the Weft fide o f
the village o f Saint Beter and Saint Paul.
Latitude deduced from meridian zenith
diftances o f the fun, and o f five itars
to the South, and five to the North of
the zenith - 53° o' 38" North.
Longitude deduced from one hundred
and forty-fix fets o f lunar obfervations
- - - 138’ 43' 16" Eaft.
Longitude by time-keeper, according to
its Greenwich rate - - 173° 36! o''
Longitude by time-keeper, according
to its rate found at Owhyhee - 159° so' o". .
Variation o f the compafs, by azimuths
taken with three compafles, made by
Knight, Gregory, and Martin - 6° 18' 40" Eaft.
Dip o f the North pole o f the magnetic
needle, being a mean o f the
obfervations taken in 'June and September
- - - ¿3° s' o"
, It was high water, on the full and change o f the moon,
at thirty-fix minutes paft four, and the greateft rife was
T t 3 five