THE METEOROLOGY OF EDINBURGH. 695 



greater frequency during winter, but there is no pronounced maximum. It is seldom seen 

 in spring, only fourteen cases being reported from March to June inclusive. 



Gales. 



Table XXIX. shows the distribution of gales throughout the year. The absolutely 

 stormiest time is from January 19 to February 6, and the calmest from June 26 to 

 July 30. The popular belief in the prevalence of storms at the spring or the autumnal 

 equinox is not supported by the data under consideration. 



Fog or Mist. 



The preparation of this table (XXX.) has been a matter of much labour, owing to 

 the different ideas prevailing among the observers as to what constitutes fog or mist. 

 It is quite evident that for some periods " haze " was entered as fog. All such 

 erroneous entries as could be detected were eliminated, but owino; to the lack of 

 uniformity in the observations, an element of error is introduced. The foggiest 

 periods are during the cold weather in January, viz., from the 9th to the 14th, and 

 from April 22 to June 26, or during the time when easterly winds are most prevalent. 

 The annual minimum is in February. 



Climatic Features of the Winds. 



It has been proved by meteorologists that the weather prevailing at any given time 

 at a place is the result of the distribution of pressure at the time. Now, since the 

 distribution of pressure regulates the direction of the wind it follows that if we wish to 

 see clearly the effect of different pressure types on the weather that the way to do so is 

 to analyse the climatic features of the various winds. We have accordingly, with the 

 able assistance of Mr Charles Stewart, B.Sc, calculated the mean temperature, mean 

 relative humidity, average amount of vapour in a cubic foot of air, and mean percentage 

 of sunshine for the various winds. 



The observations utilised for this purpose, over 10,000 in number, were taken at my 

 station in the south side of Edinburgh 254 feet above the sea, the hours of observation 

 being 9 a.m. and 9 p.m. The values given are the mean of the seven years ending 

 with June 1894. (See Tables XXXIII. to XXXVI.) 



As regards sunshine the values are for the five years ending July 1895, and will 

 be found in the last volume of the Scottish Meteorological Society's Journal* 



Temperature. — The warmest winds at Edinburgh are S., S.W., and W. The 

 warmest direction is S.W., except in August and September, when it changes to W. 

 The coldest winds, on the other hand, are N. in spring, autumn, and winter, and 

 E. in summer. S.E. winds are characterised by unusually low temperatures in 

 December and January. That severe frost often occurs with the wind in question 

 has been pointed out by the Eev. Fenwick Stow in an interesting and suggestive 

 paper published in the Royal Meteorological Society's Quarterly Journal.^ 



* Vol. x. p. 159. t Vol. xvii. p. 176. 



