3 6 
‘THE WORK OF THE OUSE.” 
j^N February of this year a series of experiments was begun 
with a view to ascertaining the amount of solid matter 
brought down by the Ouse, and of estimating the geological work 
done by that river. These experiments were of the simplest 
character; they consisted merely in drawing about half-a-gallon 
of water from the river a little to the East of Scarborough 
Railway Bridge, evaporating a litre of this water to complete 
dryness and weighing the residue thus obtained. One hundred 
and two such experiments were performed by myself and my 
assistant (Wm. Watson). Taking the mean of these results, it 
appears that every litre brings down an average amount of 215 
milligrammes ; in other words, every gallon contains 15 grains, 
or every 32 gallons one ounce, of solid matter. No attempt 
was made to ascertain the relation of matter in solution to 
that in suspension; experiments will, however, shortly be made 
with a view to determining this point. The smallest amount 
of residue was ’097 mgrmes., the largest, 385 mgrmes. On the 
former occasion the river had fallen after a small flood ; on the 
latter, the river was in high flood. As a rule, the largest amounts 
of residue were obtained when the river was low and the water 
clear. The second highest amount recorded, 336 mgrmes., 
was obtained when the river was at summer level. It is true 
that in exceptional floods the amount of solid matter was high, 
but the average residue at summer level was 223 mgrmes., 
against 211 mgrmes. during flood. These floods are mainly 
caused by rain rushing down the slopes of the north-western 
hills and swelling the head waters of the various streams 
which unite to form the river. Such rain water effects a 
large amount of mechanical waste by the mere violence of its 
