the discovery was made by Professor
Olmsted; and Mr. Herrick, of New Haven, has added valuable suggestions.
The idea that observers, differently placed at the time of appearance
and disappearance of the same meteor, would give the means of
determining differences of longitude, was first applied in our own
country, where the difference of longitude of Princeton and Philadelphia
was determined by observations of Henry and Alexander, Espy and Bache.
In meteorology our countrymen have succeeded well. Dr. Wells, of South
Carolina, elaborated his beautiful and original theory of the formation
of dew, and supported it by many well-devised and conclusive
experiments. The series of hourly observations, by Professor Snell and
Captain Mordecai, are well known; and the efforts of New York and
Pennsylvania, of the medical department of the army, and its present
enlightened head, Dr. Lawson, have much advanced this branch of science.
The interesting question, Does our climate change? seems to be answered
thus far in the negative, by registers kept in Massachusetts and New
York. There are two rival theories of storms. That of Redfield, of a
rotary motion of a wide column of air, combined with a progressive
motion in a curved line. Espy builds on the law of physics, examines the
action of an upmoving column of air, shows the causes of its motion and
the results, and then deduces his most beautiful theory of rain and of
land and water spouts. This he puts to the test of observation; and in
the inward motion of wind toward the centre of storms, finds a striking
verification of his theory. This theory is also sustained by the
overthrow or injury, in the recent tornado at Natchez, of the houses
whose doors and windows were closed, while those which were open mostly
escaped unhurt. Mr. Espy must be considered, not only here, but
throughout the world, as at the head of this branch of science. This
subject has been greatly advanced by Professor Loomis, whose paper has
been pronounced, by the highest authority, to be the best specimen of
inductive reasoning which meteorology has produced. The most recent and
highly valuable meteorological works of Dr. Samuel Forry are much
esteemed. Many important discoveries in pneumatics were made by Dr.
Franklin and Count Rumford, and the air pump was also greatly improved
by Dr. Prince, of Salem.

Chemistry, in all its departments, has been successfully pursued among
us. Dana, Draper, Ellet, Emmet, Hare, t