502 



REPORT — 1891. 



The result of this set of observations Is shown in Curve XVIII., which 

 is a particularly valuable one on account of its length and regularity. The 

 ranee of water- temperature is markedly less than that of air- temperature, 

 although not to such a striking degree as in the case of the Kennet. The 

 interesting feature of this curve is, however, that at all temperatures above 

 the annual mean for water and air the water remains cooler and there is 

 only a scarcely appreciable approach of the two curves at the seasonal 

 fall of temperature, compared with their position during the seasonal 



Monthly Means of Temperature Observations on the Wiiham at 

 Saltersford, Grantham. 



Northampton Reservoir. 



Mr. G. S. Eunson made observations for the Northampton Natural 

 History Society from January 1889 to March 1890 on a small reservoir 

 supplying water to Northampton. The reservoir stands 3G0 feet above 

 sea level on a stream near Guilsborough, eigh t miles N.N .E . of Northampton , 

 close to one of the sources of the river Nene. The observations made 

 are shown in Curve XIX., the chief features of which resemble those of 

 the Grantham curve, although they are not so pronounced. 



