418 



MR E. M. WEDDERBURN 



observations extending over the greater part of a day, and this has made it difficult 

 to examine the operation of currents. Fig. 6 shows graphically two series of observa- 

 tions made within eight hours of one another. These show entirely different types 

 of curves, and from such curves as these it is quite impossible to form any idea either 

 of the temperature distribution of the loch or of the currents which are at work to 



SurAiae 



Sofett. 



lOOfeeA. 



I50fie**. 



20ofoet. 



TortAyustuj I rQ/htyusC /90<*. 



Fig. 6. 



effect such changes. This will serve to illustrate how great is the need for simultaneous 

 observations. In this direction there is still great room for work in observing lake- 

 temperatures. In September 1904, for a short time simultaneous observations were 

 made. If we can judge from these somewhat meagre observations, the first effect of 







— Fort Augustus. 

 Inverfarigaig. 



— Dores. 



Fig. 7. 



a change of wind is to straighten out any sinuosities which appear on the isotherms. 

 The general condition of the isotherms in settled weather when represented graphically 

 reminds one of a fan. They radiate out from the windward end of the loch. When 

 the wind changes direction, this fan arrangement gradually changes with the wind. 

 Fig. 7 represents the observations made at 150 feet at this time at Fort Augustus, 



