Loch Lomond during the Autumn of 1885 327 



14/7* Xorcmbcr. It had been raining all night, but cleared 

 when I arrived at Balloch. I was accompanied by Mr Morrison, 

 from the Scottish Marine Station at Granton, who brought with 

 him three overturning thermometers. A very heavy snow 

 squall occurred on the way up the loch, but it cleared off before 

 we arrived at Inversnaid. While at Inversnaid the weather 

 was very favourable, and we had no difficulty in getting this 

 series of observations. The temperatures at 65, 85, and 100 

 fathoms were taken with my thermometers, the others were 

 taken with the overturning thermometers of the Negretti type. 

 In the afternoon a series of temperatures was taken with the 

 overturning thermometers in the Luss basin west of the Ross 

 Islands. 



The salient feature at both stations is the great cooling 

 which has taken place since I5th October. The whole body of 

 water in the Luss basin has been cooled 2\ . The temperature 

 of the bottom water at Inversnaid has risen 0-1, and it has 

 probably reached its maximum. 



Having described and discussed the observations made at 

 the different stations at the same date, it will be useful to 

 consider some of the stations with respect to the variation in 

 the distribution of temperature with changing season, and for 

 purpose it will be convenient to take two typical stations, 

 namely, that at Ross Mill in the Luss basin, which represents 

 a shallow lake, and that at Inversnaid, representing a deep one. 



7V/i f Luss Basin. Observations were made in this basin 



on 5th September, 22nd September, I5th October, and I4th 



in her. Already on the 5th September the curve has 



almost lo-t its summer feature, and is becoming pronouncedly 



autumnal. On i5th October it has assunn-d the winter form, 



ami between that date .m<l 14111 November the nearly uniform 



temperature ,.f the water ha- fallen about 2-6 F. The sui 



t. in. m 55-2 on 5th September to 53-6 on 



ptember, to 49-4 on i.sth October, and 40-0 on i4th 



mber. The autumnal /one of nearly uniform temperature 



in tl e lavt-i i \t- nd- on hth September to 15 fathom-. 



on L 5th October to the bottom, Therefore, until -om- date 



between th jjnd September and i^th October the upper 



