[M'LEOD A BARNES] ON THE DIFFERENCE IN TEMPERATURE 



147 



27th to 6 a.m. on the 29th was followed by the long period of warm 

 weather covering the greater part of the 28th, the 29th, 30th and 31st, 

 and although a normal minus deviation was recorded as early as 10 a.m. 

 on the 29th, colder weather did not set in until midnight of the 30th. 

 These results presented in tabulated form to show the interval of warning 

 of an approaching change in temperature are as follows : — 



In the c-urv^es folliowing will be seen the ditferential traces as ob- 

 tained on the records from the temperature recorder. The zero line, 

 or line of equal temperature is indicated by a thicker mark. Over the 

 zero line the differences are positive, indicating warmer on the mountain, 

 while the reverse is the case below the line. 



In the thermograph records following the ditferential traces, the 

 mountain temperature is shown"" on the trace through the small circles, 

 the other trace giving the temperature at the lower station. 



(Xote added Oct 2, 1906.) 



Tests of the insulation of the cable, made as the warm weather 

 advanced in June, showed the lines to be almost perfect, and in conse- 

 quence a "series of excellent traces has been obtained during the summer 

 months. These will be analysed and presented in a future paper. 



