On the Climate of Strathpeffer Spa. 53 
January (28 hours). The total for 1890 is 1223 hours against 
1043 in London. The percentage of possible duration is 
calculated from the approximate average length of the day 
for each month at the two stations. The highest percentages 
are found in the months April, May, and September; and it 
must follow that in these months there was a high degree of 
atmospheric transparency. It is worth observing that in 
these months the rainfall was decidedly below the average, 
as well as the number of so-called “rainy days.” 
TABLE IX. 
| { 
| Duration of Bright Sunshine in Hours. el RPE wear R 
{Saas 2: i caslans oie Bee, state PM. A BOE il i ieebetine Mla: tenet cee 
Strath- | Braemar. | Reyal Ob- | West-  Falmouth.|| Strath- | West- 
| pefter. servatory.| minster. peffer. minster. 
| 1889. | | 
| December, 30 ay 20 a | 61 15°4 2°9° 
1890. 
January, . 26) -4 24 44 39 45 12°5 15°0 
February, . 80 72 63 26 105 29°6 9-4 
March, . ad aay 91 63 | 142 27°6 17°2 
‘| ty °°} 18 141 ioe | E70 37 °6 24:1 
a 184 158 224 180 190 36°8 37°5 
guné,; . . m2 i) 937 125 107 “Toe 26°5 21°6 
August, . 133 | 114 153 158 210 28°5 35°0 
September, | 126 128 153 | 125 156 34:0 | 33-0 
October, . 84 81 97 94 137 2775 28°5 
Noveinber, yl 45 41 = ald 88 22°0 12°7 
December, 31 9 2 0 19 15°4 0:0 
ASS ee a en Pare ee | pees 
| 1890 1223 1130 1255 1042 | 1566 26°6 Ps Ne 
It should be stated that the radiation records at Strath- 
peffer are necessarily checked by the hilly contour of the 
valley. There is a wall of 500 to 700 feet on the south and 
west, which brings about a premature sunset in winter; 
whilst on the north-west of the Spa hills of from 1000 to 
1500 feet cut off from the northern side of the valley, where 
the instruments are mounted, all sunshine after about. 6.30 
P.M.; although very frequently the south side of the valley 
remains in brilliant sunshine as late as eight o’clock on a 
summer’s evening. Finally, it must be borne in mind that 
aspect, on a slope facing south or south-west, will compensate, 
in some degree, for the obliquity of the sun’s rays. 
