orded almost an equal number in the southern sky.

Of the six thousand two hundred nebulae now known the HERSCHELS
discovered at least eight-tenths. The mere discovery of twenty-five
hundred nebulae would have been a brilliant addition to our knowledge of
celestial statistics.

HERSCHEL did more than merely point out the existence and position of
these new bodies. Each observation was accompanied by a careful and
minute description of the object viewed, and with sketches and diagrams
which gave the position of the small stars in it and near it.[36]

As the nebulae and clusters were discovered they were placed in classes,
each class covering those nebulae which resembled each other in their
general features. Even at the telescope HERSCHEL'S object was not
discovery merely, but to know the inner constitution of the heavens.
His classes were arranged with this end, and they are to-day adopted.
They were:

CLASS I. "Bright nebulae (288 in all).
II. "Faint nebulae (909 in all).
III. "Very faint nebulae (984 in all).
IV. "Planetary nebulae, stars with burs, with milky chevelure,
with short rays, remarkable shapes, etc. (79 in all).
V. "Very large nebulae (52 in all).
VI. "Very compressed and rich clusters of stars (42 in all).
VII. "Pretty much compressed clusters (67 in all).
VIII. "Coarsely scattered clusters of stars" (88 in all).

The lists of these classes were the storehouses of rich material from
which HERSCHEL drew the examples by which his later opinions on the
physical conditions of nebulous matter were enforced.

As the nebulae were discovered and classified they were placed upon a
star-map in their proper positions (1786), and, as the discoveries went
on, the real laws of the distribution of the nebulae and of the clusters
over the surface of the sky showed themselves more and more plainly. It
was by this means that HERSCHEL was led to the announcement of the law
that the spaces richest in nebulae are distant from the Milky Way, etc.
By no other means could he have detected this, and I believe this to
have been the first example of the use of the graphical method, now
become common in treating large masses of statistics.

It is still in his capacity of an observer--an acute and wise one--that
HERSCHEL is considered. But this was the least of his gifts. This vast
mass of material was not left in this state: it served him for a
stepping-stone to