Loch Lomond during the Autumn of 1885 329 



stratum of water is being cooled on both sides that i>. it 

 loses heat by radiation and convection upwards into the 

 atmosphere, and by conduction and convection downward 

 into tin- lower strata of the water. By the I5th October the 

 loss downwards has ceased, and the heat lost between that 

 date and i5th November has escaped by the surface. 



TABLI-: VIII. Collected Observations in Luss Basin, 1885. 



Taking the depth at the Ross Mill station as 35 fathoms, 

 have the following values for the mean temperature of the 

 whole of the water: 



Date 5th Sept. 22nd Sept. I5th Oct. i4th Nov. 



n temperature 50-71 50-71 49*03 46-3 



II i in. an temperatures on the 5th and 22nd September 

 are identical, hence the epoch of maximum heat in the \\ 

 must fall between these two dates, and as cooling goes on more 

 rapidly than heating, it will fall nearer the 2jnd than the 5th, 

 and mav with >afety be -aid to occur in the third week of 

 September. The curves of the 5th and jjiiil September i 



depth ot i \-=) tathoms. 1 temperature at 13-5 



tathnms was the same on both these dates. But on the c;r 

 one the temperature of the water at that depth w.i 

 whet ' : one it i- tailing, therefore it mu-t : 



.ixiinum sunn- time between these dates, and no 



doubt in the third v >eptnnh ot JJiid 



;id 1 5th October interse< here 



inpeiM b.,th date- 



