begin as the smallest visible speck, and gradually grow? When
several spots coalesce into one, how do they do it? When a spot
breaks up into several pieces, what is the seeming nature of the
process? How do the groups of brilliant points called faculae
come, change, and grow? All these questions must no doubt be
answered in various ways, according to the behavior of the
particular spot, but the record is rather meagre, and the
conscientious and industrious amateur will be able to amuse
himself by adding to it, and possibly may make valuable
contributions to science in the same way.

Still another branch of astronomical observation, in which
industry and skill count for more than expensive instruments, is
the search for new comets. This requires a very practised eye, in
order that the comet may be caught among the crowd of stars which
flit across the field of view as the telescope is moved. It is
also necessary to be well acquainted with a number of nebulae
which look very much like comets. The search can be made with
almost any small telescope, if one is careful to use a very low
power. With a four-inch telescope a power not exceeding twenty
should be employed. To search with ease, and in the best manner,
the observer should have what among astronomers is familiarly
known as a "broken-backed telescope." This instrument has the eye-
piece on the end of the axis, where one would never think of
looking for it. By turning the instrument on this axis, it sweeps
from one horizon through the zenith and over to the other horizon
without the observer having to move his head. This is effected by
having a reflector in the central part of the instrument, which
throws the rays of light at right angles through the axis.