136 



Pari III. — Seventeenth Annual Report 



rain all the time. On 23rd November a large part of the shore between 

 Balmaha andEowardennan was examined, while that portion from Balmaha 

 southwards to near the month of the River Endrick was examined on 

 22nd March and 21st June 1898. 



Temperature Observations. 



The examination of the loch included, as already stated, not only tow- 

 net experiments, but the recording of the temperature of the water and 

 other necessary physical observations. The annexed Table shows the 

 various temperature readings observed each time the loch was examined. 



Table showing Temperature and other Physical Observations. 



Temperature. 



Wind. 



Position. 



Date. Hour 



Lpper end 

 of loch, off 

 Inversnaid. 



Air. 



Dens. 



1S97. 



Aug. 20 6 p.m. 



Nov. 25 1.30p.m. 45 0 

 1898. 



Mar. 3 2 p.m. 



June 29 11 a.m. 



46-5 



Water. 



Surf. 



5 Fms. lOFms 



Direction. • Force. 



Weather. 



Surface Movement 

 of Water. 



Degs. Degs. Degs. 



600 | 55J-S 



48 0 i 48 0 



42-6 | 42-5 



60-0 I 54-8 



i4 9 

 48-0 

 •42-2 

 49*2 



Lower end — 



(1) North of 



Balloch 

 Pier. 



(2) Off Bal- 

 maha. 



Aug. 19 Noon. 

 Nov. 24; 10 a.m. 

 Mar. 22! 2 p.m. 

 June 21|1. 30p.m. 



49-5 

 62-5 



4fms. 



60- 7 60-3 



5 fms. 

 47-8 4S-0 



23 ft, ; 

 42-0 | 42-0 j 



5 fms. 



61- 1 59-7 



Westerly. 

 Easterly. 

 S. West. 

 S. East. 



N. West. 

 Easterly. 

 S. West. 



Light. Dull ; fair. Slight ripple. 



Squally. Dull; fair. ; Irregular. 



Light Dulksh'wry Movem'nt moderate. 



Light, Hazyjinclin- Slight ripple, 

 squally, ing to rain. 



Light. 

 Light. 

 Light. 



Showery. 

 Dull ; fair. 

 Cloudv. 



Slight ripple. 

 Slight ripple. 

 Slight ripple. 



S. Westerly/ Light. Clear; warm. Slight ripple. 



I desire specially to state here that the temperature readings in this 

 and similar Tables throughout the present paper are according to the 

 Fahrenheit scale ; also, that the readings are those of the thermometer 

 used — they are not corrected readings ; and, as different thermometers may 

 not give exactly the same reading (the one with the other), the true 

 temperature of the water may be a little greater or a little less than that 

 stated in the Table. The purpose of these Tables, therefore, is to show 

 not so much the exact temperature of the water, but rather the variation 

 of temperature at the different depths and at the different seasons. 



It will be observed in the Table given above that the readings for 

 August and June, taken at the upper end of Loch Lomond, show a more 

 or less rapid decrease of the temperature of the water from the surface to 

 the depth of ten fathoms, but that the difference was not so great in 

 August as it was in June. It will also be observed that the readings 

 recorded in November and March exhibit little or no difference between 

 the surface and under-surface temperatures, and that the readings for 

 March are several degrees under those for November. 



The study of temperatures, when intended to be exact, is somewhat 

 difficult owing to many circumstances relating to wind, weather, 

 currents, etc., requiring to be considered. Speaking generally, however, 

 the reason for the differences referred to above may probably be the 

 following ; — In June the summer heat, though it readily influences the 



