220 MEASUREMENT OF SEDIMENTARY DISCHARGE OF RIVERS. 
In the foregoing observations I had to rely on the accuracy of Neyille’s 
tables. I have, however, reason to believe that much has yet to be 
learned as to the discharge of rivers. The state of the bed, as well as its 
average inclination, materially affect the rate of the current, and must 
modify each case. In the portion, too, of the Onny which I selected I 
found afterwards that a mill sluice, which was sometimes open and 
sometimes closed, destroyed the value of much of my work. Many 
places, however, might be selected in which these sources of error do not 
exist, or in which they might be reduced to a minimum. 
The following, taken from the record of my observations, may help 
to illustrate what has been said. The rainfall is taken from an average 
of four rain gauges situated in different parts of the basin of the Onny, 
an area of about eighty-four square miles. 
Grains in } Discharge of 
Hour of | Height on P . 
Date. 100 oz. of | sediment per | Rainfall. 
Day. eamee: Water. | minute, in lbs. 
1870. 
March Ist .... "54 
Sp eM ecieg|) LO) -Antrs ‘60 12°31 362 “64 
12 M. 23°73 847 
6 P.M. *80 36°00 1318 
10 P.M. "85 
ppl Ore 9 AM. ‘70 14:45 711 16 
12 mu. 29°85 2128 
1 P.M. 1:20 
4PM. *40 99°54 2104 ‘00 
eben LO AGI, 7G 3°19 116 
It will be seen that the rainfall of the lst March produced its effect 
on the 2nd, and that of the 2nd one much greater on the 3rd, when the 
maximum was reached. 
Remembering that the breadth of the Onny is not more than some 
forty feet, the fact that at the rate of 2,128lbs. of mud per minute is 
sometimes carried down its bed in suspension is striking. But, besides 
this, a quantity of sand and pebbles must be rolled along the bottom, of 
which no account is taken here. The difficulty of arriving at any esti- 
mate of these in large streams is very great, but I would suggest that it 
might be possible to do so in smaller ones by simply sinking a suitable 
box in the bed when the water is low: into this the larger particles would 
fall and remain for further examination, while the sediment in suspension 
would pass away. 
THE CRYPTOGAMIC FLORA OF WARWICKSHIRE. 
BY JAMES E. BAGNALL. 
In compiling this portion of the Warwickshire Flora I have 
endeavoured to bring together the various notes given from time to time 
on this subject, which are at present scattered through various works, 
so that those botanists who may feel inclined to follow up these investiga- 
tions may be able easily to see what has been done already, and also 
to decide, with little trouble to themselves, whether the plants they 
find have been previously recorded, or are additions to our county flora. 
In compiling such lists as this the great difficulty is to settle the 
