The results shewn are somewhat discordant, even after allowance has 
been made for the different conditions under which the experiments were 
performed, as regards elevation of the gauges. Still, they all point in the 
same direction, proving beyond dispute .that the lower of two gauges 
collects more rain than the upper. 
The ingenuity of meteorologists has been much exercised to explain this 
phenomenon. Many have tried to explain it away. That is, while 
admitting that the lower gauge collects more rain than the upper, they 
contend that the indication is deceptive, and that the true rainfall is the 
same in both situations. 
One theory of this class demands special notice because it has been lately 
put forward and stoutly defended by some excellent meteorologists. It is 
not new, for Sir John Herschel in his Meteorology notices it, to condemn it 
as erroneous. It is the theory that the quantity of rain received by a 
horizontal surface will depend on the angle at which the rain falls. The 
force of the wind being greater at an elevation, the slant of the rain will 
also be greater, and the quantity received by a horizontal guage will 
therefore, it is said, be less. Anyone may draw for himself diagrams which 
will prove the fallacy of this view. Nevertheless, the question may 
become complicated through the exercise of superfluous subtlety, and it is 
surprising, as well as instructive, to note what a quantity of discussion has 
been required to clear it up. The best excuse that can be made for the 
advocates of this view — and no doubt the true reason why some of them 
have been so reluctant to abandon it — is to be found in the fact that the 
amount of elevation-difference does actually vary in a very consistent 
manner with the angle at which the rain falls, being large in proportion as 
the path of the drops deviates from the vertical. This law has been fully 
proved by careful experiments recorded from time to time in British 
Rainfall, and any theory must be defective which fails to take account 
of it. 
Another view has been lately advanced, according to which the rain- 
drops in falling approach one another. Hence, it is said, the rain becomes 
gradually denser in its descent, and the lower gauge will therefore catch 
moro than the upper, although no new formation of rain takes place in the 
interval. It is not necessary to follow the line of argument by which it is 
sought to prove this approximation of the drops. It may be granted that 
all sorts of variations in their relative distribution may occur in the course 
of their descent, but it seems obvious that any approximation of the drops in 
one place, so far as it is independent of fresh formation of rain, implies an 
