off Peary Land.

The semidiurnal tidal forces vanish at the Pole and are very small over
the entire Arctic Ocean. As a consequence the semidiurnal portion of the
tide wave in these regions is almost wholly derived from the tides in
the Atlantic Ocean. The diurnal forces attain a maximum at the Pole and
produce sensible tides in the deeper waters of the Arctic Ocean. Such
tides are essentially equilibrium tides for this nearly enclosed body of
water. The diurnal portion of the Baffin Bay tide produces the diurnal
portion of the tide in Smith Sound, Kane Basin, and Kennedy Channel. In
passing from Fort Conger to the Arctic Ocean one could reasonably expect
to find a great change in the time of occurrence of the diurnal tide in
going a comparatively short distance; in other words the change in the
tidal hour for the diurnal wave would probably be considerable where the
Baffin Bay tide joins the arctic tide.

Peary's observations show that such is the case. They show that the
diurnal tide at Cape Bryant, Cape Sheridan, Point Aldrich, and Cape
Morris Jesup follows that at Fort Conger by respective intervals of
3-1/2, 5, 6, and 8 hours. They also show that in going northward from
Fort Conger to Point Aldrich the ratio of the two principal diurnal
constituents approximates more and more nearly to the theoretical ratio;
that is, to the ratio between the two corresponding tidal forces. This
is what one would expect to find in passing from a region possessing
diurnal tides derived from the irregular tides of Baffin Bay to a region
where the equilibrium diurnal tides of the Arctic become important.

The range and time of occurrence of the diurnal tide at Point Aldrich do
not differ greatly from their equilibrium values based upon the
assumption of a deep polar basin extending from Grant Land and the
Arctic Archipelago to the marginal waters off the portion of the coast
of Siberia lying east of the New Siberian Islands. But De Long's party
observed tides at Bennett Island in 1881. From these observations it is
seen that the diurnal tide has a much smaller range than would be
permissible under the hypothesis of deep water in the portion of the
Arctic Basin just referred to. The diurnal tides at Pitlekaj, Point
Barrow, and Flaxman Island are, as noted below, also too small to permit
of this hypothesis. The smallness of the diurnal tide in the cases cited
can probably be explained on no other assumption than that of
obstructing lan