646 



MR R. C. MOSSMAN ON 



derived from a smaller number of observations, which have been "weighted" so as to 

 approximately correspond with those deduced from the complete series. 



Ground 'Temperature below that in Screen 4 Feet above Ground. 



Hour. 



30th Jan. 



31st Jan. 



1st Feb. 



Mean, 13 

 Days. 





o 





o 



o 



9 



2-6 



5-1 



6-7 



53 



10 



4-9 



4-3 



7-3 



56 



13 



> • • 



5-2 







14 



4-9 



5-8 





4-7 



15 





6-3 



• • • 





16 





5-9 



8-1 





17 



5-6 



67 



7-9 



7-3 



18 



6-1 



7-5 



9-6 



7-8 



19 



6-0 



7-6 



8-2 



8-0 



20 



6-5 



63 



7-8 



73 



21 



4-7 



5.1 



6-9 



6-3 



Hence it will be seen that terrestrial radiation is at a maximum at 7 p.m., the mean 

 ground temperature being 8°*0 below that at 4 feet above it, while by 9 p.m. the differ- 

 ence had decreased to 6°"3. This probably means that after 7 p.m. the temperature of 

 the air 4 feet above the ground was cooling faster than on the surface. The greatest 

 difference observed at any hour of observations occurred at 7 p.m. on 13th February, 

 when the shade temperature was 17° '5, and the ground temperature 4° "9, a difference of 

 12 0, 6. At this hour the relative humidity was 67, and the dew-point 8°*1. 



It must be remembered that during the time the sun was above the horizon 

 the Glen was in shade, owing to the surrounding hills. It would doubtless be of 

 interest, if occasion again offers, to have a complete record of ground temperature, 

 either by direct " eye " observations or from a continuous trace derived from a thermo- 

 graph, but in the present instance the observations under discussion were accidental 

 and incomplete, owing to the observer's frequent absence from the station. 



Temperature of River Nevis and Burn. 



The temperature of the river Nevis, and of a small burn having its source in Corrie 

 Bheinnean, between Sgor-a-Mhaim and Stob Ban, was taken daily at 2 p.m. The 

 following table gives the results : — 



Month. 



River Nevis. 



Burn. 



Temp. 



Highest. 



Date. 



Lowest. 



Date. 



Range. 



Temp. 



Highest. 



Date. 



Lowest. 



Date. 



Range. 



October 



November 



December 



January 



February 



43°0 

 39-8 

 35 3 

 36-5 

 33*4 



37'6 



51°1 

 46-1 

 45-0 

 42-3 

 37-7 



51-1 



28 

 19 

 1 

 23 

 25 



37°8 

 32-1 

 32-1 

 32-0 

 32-0 



32-0 



30 

 16 and 23 

 16, 21, 23 



13 ! 3 

 14'0 

 12-9 

 10-3 

 5-5 



19-1 



43 ! 5 

 40-0 

 35-5 

 37-1 

 33-8 



38-0 



51°2 

 47-0 

 44-5 

 43-0 

 39-5 



51'2 



28 



6 



1 



9 and 23 



24 



38°2 

 32-1 

 32-1 

 32-0 

 32-0 



32-0 



30 



16 and 23 



11, 19, 22, 23 



30, 31 



Various. 



13°0 

 14-9 

 12-4 

 11-0 

 7-5 



19-2 



