640 



MR R. C. MOSSMAN ON 



Hence, on 90 days the Glen enjoyed a higher temperature than Fort-AVilliam, 

 which was warmer than the Glen on 59 days. On 1st February 1902 the Glen was 

 9°"1 colder than Fort-AVilliam, and on 31st October 1901, 5° "3 warmer, these being 

 the extremes. The greatest excess at any hour occurred on 31st October at 7 a.m., 

 when Achariach was ll° - warmer than Fort- William ; while at 10 p.m. on 1st February 

 Achariach was 14° '5 colder than Fort- William. 



Comparing the mean daily temperatures recorded on Ben Nevis with those at 

 Achariach, we find the following : — 



Number of Days on which the Summit of Ben Nevis was from 



19 

 62 

 29 

 18 

 9 

 4 

 2 

 3 

 1 

 

 1 

 

 1 

 1 

 

 

 



1 



The greatest difference of temperature on any day, between the summit and the 

 Glen, was 20° "0 on 12th November, and the greatest temperature inversion on 1st 

 February 1902, when the Glen was 14 0, 7 colder than the summit, the maximum 

 difference occurring at 10 a.m., when the temperature on the summit was 35°"5, and at 

 Achariach 15°'l, or 20°"4 colder. On the other hand, at 9 p.m. on 12th November 

 1901 the summit was 22° '1 colder than Achariach. 



18-1 to 20-0 colder 



than Achariach 



161 , 



, 18-0 



Jl 



?) )) 



14-1 , 



, 16-0 



,, 



J) )) 



124 , 



, 14-0 



)> 



') ;> 



10-1 , 



, 12-0 



)» 



)) JJ 



8-1 , 



. 10-0 



» 



)J *? 



61 , 



, 8-0 



j j 



)) ?j 



4-1 , 



, 6-0 



j j 



J) J) 



2-1 , 



, 4-0 



)) 



,, ,, 



o-i , 



, 2-0 



;j 



)j j) 



0-1 , 



, 2"0 warmer ,, ,, 



2-1 , 



, 4-0 



)? 



») ) j 



4-1 , 



, 6-0 



)? 



)) )» 



64 , 



, 8-0 



jj 



n )J 



8-1 , 



, 10-0 



M 



Jj >) 



101 , 



, 12-0 



? j 



jj ■)•} 



121 , 



, 14-0 



n 



>) n 



14-1 , 



, 16-0 



!) 



) ) ) J 



TTable III. 



