however, that we would be justified in concluding
that the rise of scientific meteorology was inspired by the invention of
instruments, for meteorology had begun to free itself of the traditional
weather-lore and demonology early in the 17th century. The Landgraf of
Hesse described some simultaneous weather observations, made without
instruments, in 1637. Francis Bacon's "Natural History of the Wind,"
considered the first special work of this kind to attain general
circulation, appeared in 1622.[2] It seems likely that the rise of
scientific meteorology was an aspect of the general rationalization of
nature study which occurred at this time, and that the initial impetus
for such progress was gained not from the invention of instruments but
from the need of navigators for wind data at a time when long voyages
out of sight of land were becoming commonplace.

[Illustration: Figure 1.--A set of typical Smithsonian meteorological
instruments as recommended in instructions to observers issued by the
Institution in the 1850's. _Top_ (from left): maximum-minimum
thermometer of Professor Phillips, dry-bulb and wet-bulb thermometers,
and mercurial barometer by Green of New York. _Lower left:_ rain gauge.
The wet-bulb thermometer, although typical, is actually a later
instrument. The rain gauge is a replica. (_Smithsonian photo 46740._)]

It should be noted in this connection that the two most important
instruments, the thermometer and barometer, were in no way inspired by
an interest in meteorology. But the observation made early in the
history of the barometer that the atmospheric pressure varied in some
relationship to visible changes in the weather soon brought that
instrument into use as a "weather glass." In particular, winds were
attributed to disturbances of barometric equilibrium, and
wind-barometric studies were made by Evangelista Torricelli, Edme
Mariotte, and Edmund Halley, the latter publishing the first
meteorological chart. In 1678-1679 Gottfried Leibniz endeavored to
encourage observations to test the capacity of the barometer for
foretelling the weather.[3]

Other questions of a quasi-meteorological nature interested the
scientists of this period, and brought other instruments into use.
Observations of rainfall and evaporation were made in pursuit of the
ancient question of the sources of terrestrial water, the maintenance of
the levels of seas, etc. Physicians brought instruments to bear on the
question of th