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NOTE ON BAROMETER AND TEMPERATURE CURVES. 



The curves on the opposite page represent the values given in the second and third 

 portions of Tables X. (page 489) and XII. (page 491). Both sets of curves are 

 drawn so as to show departures above or below the mean value for the whole day. 

 The successive hourly values are not smoothed in any way, and are joined by 

 straight lines. 



Barometer. — The two upper sets of curves show the mean height of the barometer 

 at each hour of the day, at the Ben Nevis and Fort- William Observatories 

 respectively, for each month and for the year, on the average of the thirteen years, 

 1891 to 1903 inclusive. The hours are indicated by the vertical lines, and the space 

 between each horizontal line represents 5 one-thousandths of an inch. 



Mean Temperature. — The two lower sets of curves show the mean temperature 

 at each hour at the Observatories for the same thirteen years. In these curves the 

 space between every horizontal line represents 1 degree. 



