784 



MR J. Y. BUCHANAN ON THE 



foggy weather on Ben Nevis, arranged in convenient form for study, the study of them 

 takes time. The object of this paper, however, is less to present a complete account of 

 the meteorology of the mountain in the two different classes of weather, than to present 

 the data in the form which appears the most suitable for fruitful study, leaving the 

 actual study free and open to everyone, in view of the publication very shortly of the 

 complete series of observations to the end of 1897. While, therefore, no complete 

 discussion of the data is attempted in this paper, the chief facts of interest which 

 proceed from them are noticed in the following pages. 



First, as regards the selected dates : the principle of selection has been already 

 stated. In Tables I. and II. we have the complete list of clear and of foggy spells. The 

 clear spells are indicated in Table I. by the year and month, and the day and hour at 

 which each spell begins and ends. The foggy spells, consisting only of whole days and 

 a minimum of three consecutive days, are indicated simply by the days in the 

 squares corresponding to the year and month. The observations of thirteen years, 

 namely, 1885 to 1897 (inclusive), are dealt with in this paper. 



The following short Table shows a summary of the quantity of material which was 

 avaikble on the principle of selection adopted. 



Summary of Material Used. 





Foggy Weather. 



Clear Weather. 



Month. 



No. of Spells. 



No. of Days. 



No. of Spells. 



No. of Hours. 



January, 



22 



86 



13 



606 



February, 









12 



54 



26 



1,158 



March, 









20 



78 



27 



1,335 



April, 









16 



59 



30 



1,728 



May, 









7 



27 



37 



2,228 



June, 









12 



42 



46 



2,895 



July, 









11 



46 



30 



1,502 



August, . 









17 



58 



19 



971 



September, 









16 



79 



31 



1,296 



October, 









17 



64 



21 



951 



November, 









20 



88 



19 



983 



December, 

 Totals, . 





• 



15 



66 



14 



697 







185 



747 



313 



16,350 



From it, it will be seen that 70 per cent, of the clear weather occurs in the months 

 of April, May, and June, and generally there is much more prolonged clear weather in 



