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MEAN HOURLY VALUES AT THE BEN NEVIS AND 

 FORT- WILLIAM OBSERVATORIES. 



Mean hourly values of the barometer, temperature, etc. at Ben Nevis and Fort- 

 William Observatories have been computed from the opening of these Observatories to 

 the end of 1896, and the monthly means for this period are given here as a first 

 approximation towards an average for the two Observatories. 



Table I. — The first table contains the Barometric Pressure, 1st at Ben Nevis on the 

 average of from 1st January 1884 to 31st December 1896 inclusive, 2nd at Ben Nevis 

 from 1st August 1890 to 31st December 1896, and 3rd at Fort- William from 1st August 

 1890 to 31st December 1896. The first part gives the longest average yet available 

 for Ben Nevis Observatory, the last the average for Fort-William Observatory from its 

 commencement, and the second part is the Ben Nevis average for the same period as 

 that covered by the Fort-William Observatory averages, and so suitable for comparison 

 with them. The barometer at the Ben Nevis Observatory is reduced to 32° only, that 

 at Fort- William Observatory to 32° and Sea Level. In each case the mean value for 

 the month is given in the right hand column, and in the body of the table the 

 departures in thousandths of an inch from this mean, heavy type signifying an excess 

 and italic type a defect from the mean. These hourly departures have been adjusted 

 for the difference of Midnight values by the method described in the Appendix. 



Table II. consists of three tables of temperature similar to the Barometric Pressures 

 of Table I, the mean values being given at the side, and the departures, adjusted for 

 Midnight differences, in degrees and tenths of a degree in the body of each section. 



Table III. — The mean differences of the Dry and Wet Bulbs, 1st at Ben Nevis from 

 1st May 1884 to 31st December 1896, 2nd at Ben Nevis from 1st August 1890 to 31st 

 December 1896, and 3rd at Fort-William for the same period. Following these are the 

 hourly departures of each set from the monthly averages adjusted for Midnight 

 differences. 



ROY. SOC. TRANS. BDIN. — VOL. XLTI. 3 K 



