CLYDE SEA AREA. 



657 



From the much more extensive lists of stations for which the mean annual rainfall has 

 been calculated by Dr Buchan, and published in the Journal of the Scottish Meteoro- 

 logical Society, 3rd series, vol. vii. (1884), pp. 131-152, a map of the general distribution 

 of rainfall over the district was drawn, and from the less complete data for 1886 and 

 1887 a map of the average rainfall of those two years was also constructed. For 

 assistance in preparing these maps (Plates V. and VI.) I am indebted to my friends, Mr 

 J. G-. Bartholomew and Mr B. C. Mossman. Plate VI. shows not only the very small 

 rainfall of the years in question, but also the fact that the rainfall exceeded 50 inches 

 only in the hills above Loch Doon in the east of Ayrshire, a small patch around Ardrish- 

 aig at the head of the Central Arran Basin, and an area stretching over the upper part 

 of the Dunoon Basin from the Holy Loch over the Gareloch, Lochs Goil and Long, 

 and across Loch Lomond about Tarbet. The greater part of Loch Fyne, the whole 

 drainage area of Loch Strivan, the southern part of the Dunoon and of the Arran Basin, 

 had a rainfall of about 40 inches, while over the Plateau less than 30 inches fell. 



Table VII. gives the mean of the rainfall at 18 stations, which are mentioned in 

 each of the above tables, for each month, thus serving as a rough measure of the relative 

 dryness of the period under observation and the fluctuations in its rainfall. 



Table VII. — Mean Monthly Rainfall of the Clyde Sea Area and its associated Area of Land Drainage- 



18 Stations. 





Jan. 



Feb. 



Mar. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Year. 



Mean, | 

 1866-83. j 



5-53 



4-54 



3-39 



2-62 



2-46 



2-99 



3-54 



4-17 



4-65 



5-17 



4-77 



5-22 



49-05 



Total 1886, 



5-00 



2-29 



3-19 



2 - 22 



3-28 



155 



3-04 



2-67 



5-32 



4-26 



4-82 



4-58 



42-22 



Diff. 1886, 



-0-53 



— 2-25 



-0-20 



-0-40 



+ 0-82 



-1-44 



-0-50 



-1-50 



+ 0-67 



-0-91 



+ 0-05 



-0-64 



-6-83 



Total 1887, 



4-00 



3-11 



2-02 



2-48 



1-50 



1-33 



3-25 



3-00 



3-97 



2-14 



3-34 



3-97 



34-11 



Diff. 1887, 



-1-53 



-1-43 



-1-37 



-0-14 



-0-96 



-1-66 



-0-29 



-1-17 



-0-68 



-3-03 



-1-43 



-1-25 



-14-94 



Total 1888, 



3-50 



1-40 



3-10' 



2-30 



4-00 



2-10 



5-10 



3-70 



2-00 



2-35 



6-50 



4-30 



40-35 



Diff. 1888, 



-2-03 



-3-14 



-0-29 



-0-32 



+ 1-54 



-0-89 



+ 1-66 



-0-47 



— 2-65 



-2-82 



+ 1-73 



-0-92 



-8-70 



The differences given are those from the mean. From these figures it is evident that, 

 considering the Sea Area as a whole, the minimum rainfall occurs in May. From that 

 month the rainfall increases steadily to October, falls slightly in November, and comes to 

 its maximum in January, falling thereafter more rapidly but very uniformly to May. The 

 rainfall during the period when salinity was observed, April 1886 to September 1887, 

 was, disregarding some minor fluctuations, about 1 inch less than the mean for every 

 month, but the curve ran fairly parallel, crossing the mean on two occasions only, and 

 that not to a great extent. It is obvious that the data of monthly rainfall summarised in 

 Table VII. are too meagre to justify a quantitative comparison of the two years between 

 themselves or with the mean. The 18 stations do not represent proportionally the 



VOL. XXXVI. PART III. (NO. 23). 5 G 



