=How the Weather Map Is Made.= At 8 A.M. to-day Washington time, which, by the way, is about seven o’clock at Chicago, six at Denver, and five at San Francisco, the observers at some two hundred stations in the United States and contiguous territory were taking their observations and from carefully standardized instruments noting the conditions of the atmosphere. By 8:20 A.M. the barometers at each station have been reduced to sea level, that is to say, they have been made to read what they would if they were located at the level of the ocean. Thus differences in air pressure that are due to differences in elevation are eliminated, so that they may not obscure those due to storm conditions. Then, for purposes of brevity and accuracy, the observations are reduced to cipher form, and each filed at the local telegraph office. During the next thirty or forty minutes the observations, with the right of way over all lines, are speeding to their destinations, each station contributing its own report, and receiving in return such observations from other stations as it may require. The observations from all stations are received at such important centers as Washington, New York, Chicago, and other large cities having Weather Bureau stations, and from these centers daily weather maps are printed and issued at 11 A.M. each day. [Illustration: CHART 3.—WINTER STORM, DECEMBER 15, 1893, 8 A.M. Black lines connect places having equal barometric pressure; arrows point in direction wind is blowing; figures at end of arrows show wind velocity, when it is more than light. ○ clear; ◓ partly cloudy; ● cloudy; R rain; S snow. HIGH indicates center of anti-cyclone, or high-pressure area; LOW indicates center of cyclone, or low-pressure area. Large figures show average temperature in each quadrant of cyclone.] Now turn to Chart 3. Heavy black lines (isobars, meaning equal pressure) are drawn through places having the same barometric reading. The readings are omitted from the printed Chart. By drawing lines for each difference of one tenth of an inch, the high and the low-pressure areas (called Highs and Lows) are soon inclosed in their proper circles. These lines run in oval or circular form, indicating that storms operate in the form of great atmospheric eddies; that there are central places of attraction _towards_ which the air is drawn if the disturbance be a low-pressure area, with its usual accompaniments of warm, moist, and often rainy weather, and _from_ which the air is driven if it be a high-pressure area, with cool, settled weather.