136 METEOKOLOGY [TEMPERATURE. degree, these marking out the prominent features of local climates, a knowledge of which is of so great importance to the agriculturist, the horticulturist, and the invalid. Figs. 12 and 13 represent charts of temperature of this descrip tion for the British Islands for 1870-1880 from the Jour, of Scot. Meteor. Soc., vol. vi. In the winter of the 160 110 I2O 100 60 60 40 20 4O 60 60 100 120 140 160 160 160 140 120 100 80 20 4O 60 60 100 120 140 160 160 FIG. 11. July Isothermals of the Surface of the Globe. southern hemisphere the depressing influence of the land on the temperature is but slightly felt, owing to the small FIG. 12. Mean Temperature of the British Islands in January. extent of the land surfaces and the comparatively low latitudes to which they extend southwards. In the south east of Australia and in the basin of the La Plata, a lower temperature prevails in the interior. Another prominent disturbing cause operating on the Flo. 13. Mean Temperature of the British Islands in July. mean temperature is to be found in the seasonal areas of low and high mean pressure in their connexion with the pre
vailing winds. Of these the most marked is the system of