Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1 by Various
page 17 of 281 (06%)
page 17 of 281 (06%)
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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 |
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