iles per hour. The history
of this untrue relation is curious. It was given about the end of the
18th century as based on some experiments, but with a footnote stating
that little reliance could be placed on it. The statement without the
qualifying note was copied from book to book, and at last received
general acceptance. There is no doubt that under average conditions
of atmospheric density, the .005 should be replaced by .003, for many
independent authorities using different methods have found values very
close to this last figure. It is probable that the wind pressure
is not strictly proportional to the extent of the surface exposed.
Pressure plates are generally of moderate size, from a half or quarter
of a sq. ft. up to two or three sq. ft., are round or square, and
for these sizes, and shapes, and of course for a flat surface, the
relation P=.003 _v_^2 is fairly correct.

In the tube anemometer also it is really the pressure that is
measured, although the scale is usually graduated as a velocity scale.
In cases where the density of the air is not of average value, as on a
high mountain, or with an exceptionally low barometer for example, an
allowance must be made. Approximately 1-1/2% should be added to the
velocity recorded by a tube anemometer for each 1000 ft. that it
stands above sea-level.

(W.H. Di.)

ANEMONE, or WIND-FLOWER (from the Gr. [Greek: anemos], wind), a
genus of the buttercup order (Ranunculaceae), containing about ninety
species in the north and south temperate zones. _Anemone nemorosa_,
wood anemone, and _A. Pulsatilla_, Pasque-flower, occur in Britain;
the latter is found on chalk downs and limestone pastures in some of
the more southern and eastern counties. The plants are perennial herbs
with an underground rootstock, and radical, more or less deeply cut,
leaves. The elongated flower stem bears one or several, white,
red, blue or rarely yellow, flowers; there is an involucre of three
leaflets below each flower. The fruits often bear long hairy styles
which aid their distribution by the wind. Many of the species are
favourite garden plants; among the best known is _Anemone coronaria_,
often called the poppy anemone, a tuberous-rooted plant, with
parsley-like divided leaves, and large showy poppy-like blossoms on
stalks of from 6 to 9-in. high; the flowers are of various colours,
but the principal are scarlet, crimson, blue, purple and white. There
are also double-flowered varieties, i