53 SOME NOTES ON LOCAL RAINFALL, 
be mentioned here. If there is a sharp frost for a short time, the 
brass wire carrying the pen contracts, the pen is raised, and a line is 
drawn on the diagram HIGHER than the horizontal base line, instead 
of LOWER, as it is when there is rain. There is no difficulty about 
this, as the cause is so obvious from the result ; but if the frost con- 
tinues sufficiently severe to affect the water in the receiving cylinder, 
and ice is formed, the float is raised, the pen descends, and the dia- 
gram appears to register a fall of rain. For absolute accuracy under 
all conditions of temperature, means of keeping the water in the 
receiving cylinder at a uniform temperature between the times of 
adjustment would have to be provided. 
RAINFALL AND THE RIVER TRENT. 
I have collected a considerable amount of information relating 
to the height and volume of the River Trent from day to day during 
the last three years, and have embodied the results for the year 1900 
in a diagram (pages 51, 52) for the use of the Society. The rainfall 
recorded at Burton during the same period is shown upon the 
diagram also relatively to the gauging of the river, 
I do not offer any remarks upon this matter, as I understand 
another member of the Society contemplates giving a paper upon it. 
The observations of the river have been made at Willington, at 
a point a short distance below the bridge, 
Above this point the drainage area of the River is: 
In the basin of the Trent i 650 sq. miles, 
” ” ” Tame eke 579 do, 
“6 An - Dove ae 390 do, 
Total 1,619 do. 
The estimated population is: 
In the basin of the Trent ns ae 641,000 
” ” ” Tame <* oe 1,305,000 
” ” ” Dove o aie 77,000 
Total 2,023,000 
Of this population about 1,628,000 is Urban and 395,000 is Rural. 
