OP THIS 
JANUARY TO MAY, 1872. 
GENERAL. 
I. 
A Puzzle in Bain, and an Attempt to Solve it. 
By George F. Burder, M.D., F.M.S. 
Head at the General Meeting, February 1st, 1872. 
[Abstract.] 
For more than a hundred years it has been known that of two rain- 
gauges in the same locality, one placed on the ground, the other at an 
elevation above the ground, the upper will collect less rain than the lower. 
The upper gauge may be placed on the roof of a house, or it may be elevated 
on a pole — the result will be substantially the same. Dr. Heberden was 
the first to notice this curious fact, and his experiments are recorded in the 
Philosophical Transactions for 1769. Some idea of the history of the 
inquiry from that time to the present maybe gathered from the following 
table, but it should be added that within the last ten years observations 
have been greatly multiplied. 
TABLE I. 
DECEEASE OF BAIN WITH ELEVATION. 
Decrease 
Date. 
Authority. 
Position of 
lower gauge. 
Position of 
upper gauge. 
per cent, 
in upper 
gauge. 
1767 
Heberden 
Below top of house 
Top of house 
20 
1829 
Roof of Westminster Abbey 
46 
Arago 
10 feet 
98 feet 
15 
1834 
Phillips 
Ground 
44 feet 
23 
213 feet 
42 
1853-62 
W.C.Burder 
6 inches 
50 feet 
12 
1864-67 
Col. Ward 
1 foot 
20 feet 
6 
1870 
Glaisher 
5 inches 
51 feet 
38 
>> 
Chrimes 
1 foot 
25 feet 
13 
