THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
293 
will be evident that the higher cultivation of recent years, of 
which tile draining is an essential concomitant, must tend to 
discharge water more rapidly into the valleys. Drainage has 
for its object the rapid removal of surplus water, and, if it 
does not do this more quickly than nature, it is difficult to 
guess its use ; it cannot even convert the land into a sponge 
without first ejecting the water from such land. 
The prevalence of the opinion that drainage causes floods 
is shown by the provision in the Rivers Conservancy and 
Floods Prevention Bill, brought forward in 1888, for taxing 
the uplands to the extent of one-tenth for improvements in 
the lowlands. Whether this was just or not, and whether 
the assumed proportion of responsibility for floods was satis¬ 
factory, I will not pretend to say, but the bill had been 
preceded, a few years before, by an examination of witnesses 
before a committee of the House of Lords. These witnesses, 
although differing much as to the causes of floods, were fairly 
unanimous in the opinion that floods were more common and 
higher than formerly, though in some cases they did not last 
so long. 
Efficient draining permits farm work to be renewed very 
soon after the cessation of rain, and almost always within the 
limits of time represented by the commencement and termi¬ 
nation of the flood, supposing the rainfall sufficient to cause 
such, and if so, the water removed must have been added to 
that reaching the valley otherwise, and so assisted in causing 
and increasing that flood. 
The sponge theory of drainage chiefly applies to periods 
in which the rains are separated by intervals of dry weather, 
for instance summer time, when a considerable rainfall is 
required to produce floods at all. Drainage alone will never 
desiccate the soil; the moisture held by capillary attraction 
will not be removed at times when the humidity of the 
atmosphere prevents evaporation, hence rapidity of action in 
the drains is essential for the soil and subsoil to have any 
absorptive capacity under such conditions, and these are the 
most natural conditions during the winter flood period. 
Properly laid drains do very promptly begin to act after 
rain, and herein lies the chief disadvantage incident to 
drainage. The water is so rapidly carried away when from 
other sources there is plenty, that much less is left for 
sustaining the springs in summer. Unless the drains are 
laid very deep in a stiff soil, or the area drained is large com¬ 
pared with the number of drains in it, they will cease to act 
about May, whereas natural springs, supplied by the same 
winter rainfall, will often continue to improve during the 
