These changes give a variety to our climate which is, on the whole, very beneficial to man. The North Temperate Zone, with strong seasonal changes in temperature and weather, is the zone of the highest civilization and of the greatest energy of man. In the Torrid Zone the changes of temperature are, as a whole, small. There is no harsh winter. The climate is monotonous and deadening, rather than enlivening. Man finds it easy to live without much work, and the inhabitants of the Torrid Zone have not, as a rule, advanced far in the scale of civilization. The =wind vane= used by the Weather Bureau is about 6 feet long, and has a divided tail made of pine boards, the two pieces making an angle of 22-1/2°. The purpose of this divided tail is to steady the vane and to make it more sensitive to light currents. [Illustration: FIG. 3.] A common wind vane on a neighboring church steeple or flagstaff will usually serve sufficiently well for ordinary use. Observations of wind direction (to eight compass points) are to be made as a part of the ordinary weather record, and to be entered in the proper column of the record book. The =rain gauge= consists of three separate parts, the receiver _A_, the overflow attachment _B_, and the measuring tube _C_. [Illustration: FIG. 4.] The inside diameter of the top of the receiver in the standard Weather Bureau gauge is 8 inches (at _a_ in Fig. 4). This receiver has a funnel-shaped bottom, so that all the precipitation which falls into it is carried at once into the measuring tube _C_, whose inside height is 20 inches. The diameter of the measuring tube is 2.53 inches. The rain falling into the receiver _A_ fills this tube _C_ to a depth greater than the actual rainfall, in proportion as the area of the receiver is greater than the area of the measuring tube. In the standard Weather Bureau gauges the ratio of the area of the receiver to the area of the measuring tube is such that the depth of rainfall is magnified exactly ten times. The object of magnifying the amount in this way is to measure a very small quantity more easily. The narrow portion of the receiver [_d_] fits over the top of the measuring tube, holding the latter firmly in place and preventing any loss of rainfall. An opening, _e_, in the lower portion of the receiver [_d_], just on a level with the top of the measuring tube, serves as an escape for the water into the overflow attachment _B_, in case the rainfall is so heavy as to more than fill the tube. The inside diameter of the overflow attachment is the same as that of the receiver (8 inches), as will be seen from the figure.