THE METEOROLOGY OF EDINBURGH. 473 



excess of the black bulb over the shade temperature diminishes rapidly. A slight rise 

 follows, but the values remain low till the 16th. Between September 17 and October 

 9 the values do not show much variation, but there is a very noticeable fall in the ten 

 days succeeding October 9. This period has more rainy days than any other time of 

 the year. After a slight increase from the 20th to the 25th of October solar radiation 

 diminishes till the annual minimum at the end of December. A few and unimportant 

 interruptions in the general decline take place from time to time. 



N on- Instrumental Phenomena with Different Winds in Edinburgh from 1857 to 1900. 



(Tables XVII. to XXVI) 



The observations discussed are those taken during the forty-four years 1857-1900 

 at the Edinburgh stations of the Scottish Meteorological Society. The place of 

 observation during nearly the whole time was in the Newington district, so that the 

 various registers are strictly comparable. The daily weather notes for the period under 

 review were read, and notices of snow, hail, gales, thunderstorms, lightning without 

 thunder, fog, solar and lunar halos and auroras extracted along with the direction of 

 the wind at the time. Tables were then prepared showing the number of times these 

 phenomena occurred, with winds from the N., N.E., E., and so on, for the eight principal 

 directions, and with calms. These tables, although necessary as an essential preliminary, 

 are of little use without a table (see Table XXV.) showing the number of days the 

 wind blew from the various directions, it being quite evident that the number of gales 

 experienced with a West wind will depend, other causes being equal, on the frequency 

 with which the wind in question prevailed. For example, the mere statement that 320 

 gales were experienced from the South- West and 66 from the East during the period 

 under review conveys but little information, but when we have ascertained that the 

 South-West wind blew on 2118 days, and the East wind on 2542 days, we are able to 

 say that 15*1 per cent, of the days characterised by a South- West wind were stormy, 

 but only 2*6 per cent, of the days on which the East wind blew. The more prominent 

 results are expressed in percentages in Table XXVI. 



Snoiv. (Table XVII.) 



In discussing statistics of snow the values were computed for the six months 

 November to April as very few cases were observed in October and May. The 

 snowiest direction is N.E. with 25*6 per cent, of snowy days, closely followed by North 

 with 21 '5, and East with 16*5 per cent.; the lowest value is with S.W. winds, only 3'4 

 per cent, being accompanied by snow. It is evident that the temperature of the air 

 has a great deal to do with the occurrence of snow, the coldest winds, as was to be 

 expected, being those with which snow most frequently falls. 



