116 
that the difference between the relative amounts in the 
different periods at the two stations is greatest in the first 
period and is almost inappreciable in the third; while in 
the second period it is very nearly the same as in the fourth. 
During the eleven hours of the third period the fall of rain 
at both stations is almost exactly half the amount for the 
entire day, the exact proportions being for Greenwich *490, 
and for Lisbon, *499. 
At some of the Russian meteorological observatories 
measures of rainfall have been taken twice daily — generally 
at 8 a.m. and 8 p.m. ; and at several of these stations the 
same law of distribution prevails as at Greenwich and 
Lisbon, namely, the fall of rain during the night exceeds 
that of the day ; but at others the day amount exceeds that 
of the night. Thus at St. Petersburg and Sitka the 
amounts are 
8 a.m. to 8 p.m. 8 p.m. to 8a.m. 
Inches. Inches. 
St. Petersburg 6 '090 * 7*945 
Sitka 36*618 43*976 
while at Bogoslovsk, Lougan and Tiflis they are as 
follows : — 
8 a.m. to 8p.m. 8 p.m. to 8 a.m. 
Inches. Inches. 
Bogoslovsk 8*071 6*962 
Lougan 8*368 5*388 
Tiflis 10*833 7*601 
It seems probable, from the results of the above discussion 
of the Greenwich and Lisbon observations, that in the cases 
in which the amount of rainfall during the day period 
exceeds that of the night, the excess will be found to be 
due not so much to a diminution in the maximum of the 
night as to an increase in the maximum of the day. It is, 
however, very desirable that this point should be deter- 
mined by observations made at suitable hours for a period 
of not less than a year ; and that the atmospheric conditions 
upon which the difference between the day and night 
amounts is dependent should be ascertained. 
