ig6 Mr. Wollaston’s description, &c. 
thermometrical barometer stood at 773,5. Difference = 1 12,4. 
2 33 : 535 :: 112,4 : 258. Correction = ZgL G f height = 19,2 
feet. Corrected height =258+ 1932 = 277,2 feet. General 
Roy’s measurement, allowing for the difference of the sta- 
tions, is 279 feet. 
