46 RESULTS OF METEOROLOGICAL OBSERVATIONS. 



August ;. the August range is nearly one-third the vakie reached in midwinter. 

 Average value O'^-GO. 



The average atmospheric pressure for the year (from 27 years of observation of 

 extremes) is 29.28 inches;^ the barometer never rose above 30.00 inches (at 32° 

 Fah.), which was attained four times in January; and never fell below 28.30 

 inches, which was attained in November. Absolute range 1.70 inches. At Bruns- 

 wick we had extreme highest value 31.00 inches (at 32°), extreme lowest 28.60 

 inches, and absolute range 2.40 inches. 



* Supposing the average pressure at the sea level in latitude 39° equal 30'".03 (at 32 Fah.) and 

 a difference of level of 91.6 feet (at a temperature of 53° Fah.) for every tenth of an inch of baro- 

 metric pressure, the above average value for Marietta would assign to it a height above the sea of 

 687 feet, which is considerably too high ; the index error of the barometer is not known. 



PUBLISHED BY THE SMITHSONIAN INSTITUTION, 

 WASHINGTON CITY, 



SEPTEMBEE, 1867. 



