Ei, L. DeForest on Reducing Meteorological Observations. 321 
months. The reason why the computed values do not agree 
exactly with the observed ones is, that the curve of the form 
y=a-+a, sin(r—e,), 
years’ observation at Albany, from 1826 to 1849 pe i? i 
by F. B. Hough in the “New York Meteorology.” 
total amounts of rain and — snow and hail for the saiaidat 
months, in inches of depth, ar 
2°91 2°88 4°09 3°76 ‘ 
2°62 4-04 3°44 3°30 
3°02 — 4:50 347 2°98 
Dividing each of these by the number of days in the month, we 
have the following values of cred mean daily rain-fall, for calen- 
dar months, in decimals of an in 
939 “0960 “1319 1213 
"0928 "1303 "1110 “1100 
0974 "1500 "1157 0961 
Now applying the correction, we obtain the mean daily rain-fall 
for mean months, 
09 
and the equation of the curve is found to be 
ment 123-4: 0202 sin{z— 106° 43’)+-0106 sin 2(z— 107° 10’) 
+-0112 sin 3(r—14° 11 am 0031 sin ipa 7’) 
+--0024 sin 5(z—56° 40’)4+-0015 sin 
e assign to a the value appropriate om any given day in 
the Pies the resulting value of y will be the average dept 
a -fall at Albany for that day, expressed in decimals of an 
After an equation has been obtained, there ought to be some 
