CLYDE SEA AREA. 



659 



ranged from 12*60 inches to 1678 inches; and in the fourteen years 1870-1883 the 

 mean annual evaporation in a large tank evaporimeter at Strathfield Turgiss was 18*03 

 inches, varying from 13*66 inches in 1879 to 23*61 inches in 1870. Mr Symons' 

 discussion contains many valuable data connecting the evaporation with rainfall and 

 surface temperature ; but, on account of the very general nature of any conclusions 

 which could be arrived at on the subject, I hesitated to undertake the labour of 

 recalculating the conditions deduced from the less complete estimate. 



Studying the rainfall maps (Plates III. and IV.) it was possible to make a rough estimate 

 by inspection of the probable average rainfall over the entire drainage basin of each of 

 the main divisions. The data were not numerous enough to place reliance on measure- 

 ments of the areas lying between the several isopluvial lines. Table VIII. gives the 

 various areas, the mean annual rainfall, the actual rainfall for 1886-87, and the volume 

 in parts of a cubic sea mile of rain-water assumed to reach each of the basins in a year 

 after evaporation is deducted. It appears that in the years of observation only f of the 

 average amount of fresh water could have reached the basins. 



Table VIII. — Estimate of Volume of Rain falling on the Clyde Sea Area and the in-sloping Land, 

 deducting the Evaporation, estimated as 15 Inches per Annum over Land and Narrow Lochs, 

 25 Inches over Arran Basin and Plateau Water- Surfaces. 







Sq. Sea Miles. 

 Area.* 



R. 



Average 

 Rainfall. 

 Inches. 



R.-E. 



Rainfall - 

 Evapora- 

 tion. 



R.-E. 



Rainfall - 



Evaporation. 



Sea Miles. 



Volume. 



R. - E. Cuhic 



Sea Miles. 



1886-87. 

 Rainfall. 

 Inches. 



R. -E. 



, 1886-87. 



Volume. 



R.-E. Cubic 



Sea Miles. 





Inches. 



Sea Miles. 





12-8 

 28-9 



60 

 75 



45 

 fiO 



0-00063 

 0-00090 



0-00806 

 0-02601 



55 

 55 



40 

 40 



0-00056 

 0-00056 



0-00717 

 0-01618 



2. Loch Goil, 





3. Loch Long, . 





25-8 



80 



65 



0-00093 



0-02399 



55 



40 



0-00056 



0-01445 



4. Holy Loch, . 





57-4 



70 



55 



0-00080 



0-04592 



50 



35 



0-00050 



0-02870 



5. Loch Strivan, 





37-8 



60 



45 



0-00063 



0-02381 



40 



25 



0-00036 



0-01361 







60-5 



65 



50 



0-00072 



0-04356 



40 



25 



0-00036 



0-02178 



7. Loch Fyne, . 





168-0 



70 



55 



C -00080 



0-13440 



45 



30 



0-00042 



0-07056 



8. Dunoon Basin, 





107-0 



60 



45 



0-00063 



0-06741 



45 



30 



0-00042 



0-04494 



Clyde proper (to Bow- 























886-0 



40 



25 



0-00036 



0-31896 



35 



20 



0-00030 



0-26580 



Estuary (excluding 



Loch Lomond), 



67-4 



50 



35 



0-00050 



0-03370 



45 



30 



0-00042 



0-02831 



Loch Lomond, . . 



228-0 



75 



60 



0-00090 



0-20520 



50 



35 



0-00050 



0-11400 



9. Arran Basin (water), . 



531-0 



45 



20 



0-00030 



0-15750 



30 



5 



0-00008 



0-04200 



,, (land), . . 



835-0 



50 



35 



0-00050 



0-41750 



35 



20 



0-00030 



0-25050 



10. Plateau (water), . . . 



243-0 



40 



15 



0-00021 



0-05145 



30 



5 



0-00008 



0-01960 



„ (land), . . . 



Total Mean, . . 



Total, minus Arran Basin 



217-0 



45 



30 



0-00042 



0-09114 



30 



15 



0-00021 



0-04557 



3505-6 



52 



35 



0-00050 



1-64891 



38 



20 



0-00028 



0-98317 





















and Plateau, .... 



1679-6 



55 



40 



0-00055 



0-93132 



40 



25 



0-00037 



0-62550 









R. in Sea 









R. in Sea 





Kainfall irrespective of Eva- 









Miles. 









Miles. 







3505-6 



52 





0-00075 



2-64600 



38 





0-00055 



1-81600 



* Land and water included, except where otherwise mentioned. The proportion of rainfall lost by evaporation is that 

 suggested hy Dr A. Buchan. 



From Table VII. the percentage of the annual rainfall which occurred in each 

 month was calculated, and that applied to Table VIII. gave the following estimate 

 (Table IX.) of the distribution of volume of inflowing fresh water : — 



