and during a
large percentage of the time these were supplemented by observations
taken more frequently, often at intervals of ten minutes each.

The chronometer used in connection with tidal work was compared with
true Greenwich time at New York before and after the cruise to the
Arctic. The comparisons showed that during this period of 461 days the
average daily gain of the chronometer was 2.2 seconds.

The mean lunitidal intervals and the mean ranges of tide, together with
the approximate geographical positions of the stations, are as follows:

-----------------+---------+---------+---------+---------+----------
| | | HW | LW |Mean Rise
Station |Latitude |Longitude|Interval |Interval | and Fall
-----------------+---------+---------+---------+---------+----------
| deg. ' | deg. ' |_h_ _m_ | _h_ _m_ | Feet
Cape Sheridan | 82 27 | 61 21 | 10 31 | 4 14 | 1.76
Point Aldrich | 83 07 | 69 44 | 7 58 | 1 50 | 0.84
Cape Bryant | 82 21 | 55 30 | 0 03 | 6 22 | 1.07
C. Morris Jesup | 83 40 | 33 35 | 10 49 | 4 33 | 0.38
Fort Conger | 81 44 | 64 44 | 11 35 | 5 15 | 4.06
Fort Conger[6] | 81 44 | 64 44 | 11 33 | 5 20 | 4.28
-----------------+---------+---------+---------+---------+----------

The harmonic constants for these places will be given in a paper on
Arctic Tides about to be issued by the Coast and Geodetic Survey.

As indicated by its name, a "lunitidal interval" is the time elapsing
between the passage of the moon across the meridian of the place or
station and the occurrence of high or low water. If two stations have
the same longitude, then the difference between the lunitidal intervals
for the two stations denotes the difference in the times of occurrence
of the tides. If they have not the same longitude, then the intervals
must be converted into lunar hours (1 lunar hour = 1.035 solar hours)
and increased by the west longitude of the stations expressed in hours.
The result will be the tidal hours of the stations expressed in
Greenwich lunar time. The difference between the tidal hours for two
stations will be the difference in the time of occurrence of the tides
expressed in lunar hours.

One of the most important results brought out from the tidal
observations of the expedition is the fact that high water occurs two
hours earlier (in absolute ti