Bartlett—The Cold-Waves of BouthYCentral Wisconsin . 295 
November 18-19, 1896, —40° in 24 hours. 
November 26, 1896, —34° in 10 hours. 
January 24, 1900, —32° in 10 hours. 
April 29, 1903, —42° in 17 hours. 
March 2, 1904, -—32° in 10 hours. 
January 19, 1907, —44° in 12 hours. 
The rapidity of the temperature fall in a few hours is also 
often remarkable, though not equaling in abruptness the 
falls during thunderstorms. 
Some instances of such marked falls are noted in the table. 
During the winter months many cyclonic storms pass across 
the country without causing cold waves in Wisconsin. It be¬ 
comes of interest, therefore, to study the 7 a. m. weather map 
preceding a number of cold-waves in this section. Dor this 
purpose the accompanying table has been prepared, showing 
in condensed form, the principal weather map features for all 
Madison cold-waves since December, 1904, 18 in all. This 
table presents the location, and strength of central isobar, of the 
cyclonic (Low) and anticyclonic (High) areas influencing 
Wisconsin weather, the 7 a. m. temperatures in the Dakotas 
