UNCERTAINTY OF METEOROLOGY. 
23 
station upon the results of observations of temperature and 
precipitation. A thermometer removed but a few hundred 
yards from its first position differs not unfrequently five, some¬ 
times even ten degrees in its readings ; and when we are told 
that the annual fall of rain on the roof of the observatory at 
Paris is two inches less than on the ground by the side of it, 
w r e may see that the level of the rain-gauge is a point of much 
consequence in making estimates from its measurements. The 
data from which results have been deduced with respect to 
the hygrometrical and thermometrical conditions, the climate 
in short, of different countries, have very often been derived 
from observations at single points in cities or districts separated 
by considerable distances. The tendency of errors and acci¬ 
dents to balance each other authorizes us, indeed, to entertain 
greater confidence than we could otherwise feel in the conclu¬ 
sions drawn from such tables; but it is in the highest degree 
probable that they would be much modified by more numer¬ 
ous series of observations, at different stations within narrow 
limits.* 
* The nomenclature of meteorology is vague and sometimes equivocal. 
Not long since, it was suspected that the observers reporting to a scientific 
institution did not agree in their understanding of the mode of expressing 
the direction of the wind prescribed by their instructions. It was found, 
upon inquiry, that very many of them used the names of the compass- 
points to indicate the quarter from which the wind blew, while others 
employed them to signify the quarter toward which the atmospheric cur¬ 
rents were moving. In some instances, the observers were no longer 
within the reach of inquiry, and of course their tables of the wind were of 
no value. 
“ Winds,” says Mrs. Somerville, “ are named from the points whence 
they blow, currents exactly the reverse. An easterly wind comes from 
the east; whereas an easterly current comes from the west, and flows 
toward the east .”—Physical Geography, p. 229. 
There is no philological ground for this distinction, and it probably 
originated in a confusion of the terminations -wardly and - erly , both of 
which are modern. The root of the former ending implies the direction 
to or to-ward which motion is supposed. It corresponds to, and is prob¬ 
ably a 1 lied with, the Latin versus. The termination -erly is a corruption 
or softening of - ernly , easterly for easternly, and many authors of the sev- 
