1 68 
president’s address. 
the waves of which he has detected by his limnograph 
25 minutes before the arrival of the boat itself, and for as 
much as 2 to 3 hours after they have passed. 
The Sutton laboratory has a recording tide gauge, and 
observations have been taken at Sutton and elsewhere, but 
as yet with not sufficient completeness to allow definite 
conclusions to be drawn as to the movements of the water 
in our rivers. 
I show, however, a few charts, which may be of interest 
as far as they go. 
It is not safe to dogmatize from this small number of 
observations ; but the following figures deduced from them 
are perhaps worth putting before you. 
The tidal wave reaches Acle Bridge 2 \ to 3J hours after 
it reaches Yarmouth Bar ; Thurne Mouth about 3! hours ; 
above Ludham Bridge about 10 hours ; and Sutton Broad 
15J to 19 hours. Of experiments made at Sutton, Irstead 
Shoals, Ludham, and Acle, the greatest difference between 
one high and the succeeding low water has been 9 inches at 
Acle, i.e., a wave of 4J inches, while frequently at Sutton 
there has been no measurable rise and fall. 
The average at Sutton for the period June 14th to 21st of 
last year was .195 inches. 
I would like to call particular attention to the fact that 
the well-known pleasure steamer, “ The Queen of the Broads,’' 
caused a wave or tide of 4J inches (=rise and fall together 
of 8J) at Acle, and that the passing of wherries at Irstead 
Shoals has caused a far bigger wave than any which are due 
to tidal influences. 
I hope this year to investigate the movements of our 
waters more fully, and by means of a second tide gauge to 
trace more accurately the course of the wave up the rivers. 
Besides the transparency, the colour of the lakes has been 
studied with great care by Forel and Delebecque. 
