riodic character. To establish this as a fact, and to measure the
period, was left for our own times and for the indefatigable observer
SCHWABE. The probable importance of such a period in its relation to
terrestrial meteorology was not only clearly pointed out by HERSCHEL,
but he even attempted to demonstrate, from such data as were obtainable,
the character of this influence.

Perhaps no one thing which this great philosopher has done better
exhibits the catholic character of his mind than this research. When the
possible connection of solar and terrestrial phenomena occurred to him
as a question to be tested, there were no available meteorological
records, and he could find but four or five short series of
observations, widely separated in time. To an ordinary thinker the task
would have seemed hopeless until more data had been collected. But
HERSCHEL'S fertile mind, though it could not recall lost opportunities
for solar observations, did find a substitute for meteorological records
in the statistics of the prices of grain during the various epochs.
It is clear that the price of wheat must have depended upon the supply,
and the supply, in turn, largely upon the character of the season.
The method, as ingenious as it is, failed in HERSCHEL'S hands on account
of the paucity of solar statistics; but it has since proved of value,
and has taken its place as a recognized method of research.

_Researches on Nebulae and Clusters._

When HERSCHEL first began to observe the nebulae in 1774, there were
very few of these objects known. The nebulae of _Orion_ and _Andromeda_
had been known in Europe only a little over a hundred years.

In 1784 MESSIER published a list of sixty-eight such objects which he
had found in his searches for comets, and twenty-eight nebulae had been
found by LACAILLE in his observations at the Cape of Good Hope. In the
mere discovery of these objects HERSCHEL quickly surpassed all others.
In 1786 he published a catalogue of one thousand new nebulae, in 1789 a
catalogue of a second thousand, and in 1802 one of five hundred. In all
he discovered and described two thousand five hundred and eight new
nebulae and clusters. This branch of astronomy may almost be said to be
proper to the HERSCHELS, father and son. Sir JOHN HERSCHEL re-observed
all his father's nebulae in the northern hemisphere, and added many new
ones, and in his astronomical expedition to the Cape of Good Hope he
rec