Page:Proceedings of the Royal Society of London Vol 69.djvu/76

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68
Messrs. W. N. Shaw and E. W. Cohen. On the Seasonal

several maxima which occur at irregular intervals, showing that the relative frequency of the two types of weather^ plays no part in causing the second-order effect. Finally, by multiplying the percentage differ- ence of frequency of cyclonic and anticyclonic weather for each month, by the difference in temperature (excess of the cyclonic, in each case,


DIAGRAM 2.

EFFECT OF TYPE (CYCLONIC OR ANTICYCLONIC) OF WEATHER ON TEMPERATURE. KEW 1876 TO 1880.

DEC.JAK.FEB. MAR. APR.HW JUN. JUl. AUG. SEE OCT. NOV. DEC. + 4

fi'6. 1 Divergence from first order curve Thick during cycLonic weather,

Fjt>.. CycLonic temperature -AnticycLonic. rm.<s. Frequency of cycLomc- Frequency ofanCicycLonic Expressed AS percentage of tat&i number of days

Fit>.4. Effect of the type <f weather on the. divergence from first; order curve.

being taken as positive, and vice versd), a resulting curve (fig. -1) is obtained which gives the total effect of the type of weather on the atmospheric temperature. A glance at this curve will show that this effect is in no respect similar to the second-order effect. It is thus evident that the cyclonic or anticyclonic type of the weather plays no part in causing the second-order effect, which is nevertheless the only prominent periodic temperature variation which has a meteorological origin.