48 Proceedings of the Royal Physical Society. 
rainfalls. At a few miles distance among the hills to the 
west of the Spa, the precipitation is nearly doubled, and across 
the country at Strome it is more than doubled. Tables VI. 
and VII. give first the monthly distribution of rainfall and 
the number of rainy days, and secondly a comparative view 
of the rainfall at several Scottish stations, with the years on 
TABLE VII. 
Station. Date. Inches. 
| 
Sandwick, . : ; : ; 1860-83 37°23 
Strome Ferry, . ; 1872-83 65°30 
Dunrobin, . ‘ : : ; 1860-83 30-08 
Invergordon, : ‘ : 1865-83 27°26 
Dingwall, . ! ; 1865-81 27°50 
Strath peffer, ' : ; 1885-90 29°43 
Culloden, . ; : : : 1860-83 26717 
Nairn, , : ; : : 1863-83 23°92 
Edinburgh, ; : : ‘ 1860-83 28°31 
Glasgow, . Stare sad ; 1860-83 43°00 
which the averages have been calculated. At Strathpeffer 
the driest year of the series was 1887 (26°36 inches) ; the 
wettest 1890 (33°76 inches). The last-named year also 
furnishes the wettest month of the entire period—viz., 
October—with a fall of 6:11 inches. There have been in the 
six years besides this instance three months when the rain- 
fall touched 5 inches, once each in January, July, and 
November. On nine occasions it has fallen below 1 inch. 
Tt is observable that nearly one-half of the annual rain occurs 
in the four months October to January. February has a low 
rainfall; April, May, and June form together the driest 
period of the year, June having the lowest monthly average. 
From May to July the record is slightly below that of London 
for the corresponding period. November is so far the wettest 
month of the year. 
SOLAR RADIATION, 
It remains to give some account of the solar radiation at 
Strathpeffer Spa, in so far as the present limited observations 
permit. A brief consideration of the influence of latitude 
