Fig. 3. The rainfall-data at the top of the figure give the monthly rainfall in millimetres (data from Monthly Weather Reports, Birmingham 
Station). The middle curve shows the height of the water of Hawkesley Hall Pond for each month (in centimetres) below the maximum 
height attainable. The lowest curve represents the variation in the total amount of dissolved matter in the water of Hawkesley Hail 
Pond, the figures being “ degrees ” (parts per 100,000 of water). See Section IV for further details. 
