ON THE SEASONAL VAEIATIONS OF TEMPERATURE. 



507 



Monthly Means of Temjperatnre Ohservations on the Earn at Bridge 

 of Earn. 



Curve XXIV.— Earn at Bridge of Barn. 

 8.45 A.M, 



CUKVE XXV.— Tay at Perth. 

 8 to 10 A.M. 



Tay and Bra an. 



Observations on tbe Tay at Perth were made at different hours 

 in the forenoon and afternoon by Mr. W. Wilson (see Curve XXV.), 

 Mr. R. Dow, and Mr. Mechie for a few mouths in 18 S8. The morning 

 observations are most interesting to compare with other rivers, and they 

 alone are given. The record is too short to admit of any attempt at 

 discussion. The same observers made a series of observations in 1887 

 and 1888, but not in the conditions required by the Committee. 



At Inver, near Dunkeld, Messrs. C. and J. Macintosh made observations 

 on the rivers Tay and Braan from March 17, 1889, to June 20, 1890, at 

 8.15 A.M. The Tay at the point of observation is narrow and deep, with 

 a comparatively slow current when the river is low. In flood instances 

 have been known of the water-level rising as much as 16 feet above 

 the average. The banks are high and wooded to the margin of the stream. 



