and heard on the observer's headgear; but on returning to the house,
nothing can be discovered on the clothing. Where the sign for snow
occurs in the column for Remarks, it means drift; these days are
included among days of precipitation. Sleet was observed only once,
in December. Rain never.

Cloudiness.

The figures indicate how many tenths of the visible heavens are covered
by clouds (or mist). No instrument is used in these observations;
they depend on personal estimate. They had to be abandoned during
the period of darkness, when it is difficult to see the sky.

Wind.

For measuring the velocity of the wind the expedition had a cup
and cross anemometer, which worked excellently the whole time. It
consists of a horizontal cross with a hollow hemisphere on each of
the four arms of the cross; the openings of the hemispheres are all
turned towards the same side of the cross-arms, and the cross can
revolve with a minimum of friction on a vertical axis at the point of
junction. The axis is connected with a recording mechanism, which is
set in motion at each observation and stopped after a lapse of half a
minute, when the figure is read off. This figure denotes the velocity
of the wind in metres per second, and is directly transferred to the
tables (here converted into feet per second).

The monthly means vary between 1.9 metres (6.2 feet) in May, and 5.5
metres (18 feet) in October; the mean for the whole ten months is 3.4
metres (11.1 feet) per second. These velocities may be characterized