horizon, one diagonal of the square being vertical, the other nearly
horizontal. Above the square is Andromeda, to the right of which lies
Cassiopeia, the stars [beta] and [epsilon] of this constellation lying
directly towards the north-west, while the star [alpha] lies almost
exactly midway between the zenith and the horizon. Above Andromeda, a
little towards the left, lies Perseus, Algol being almost exactly
towards the west and one-third of the way from the zenith towards the
horizon (because one-third of the way from the centre towards the
circumference of the map). Almost exactly in the zenith is the star
[delta] Aurigæ.

The four maps are miniatures of Maps I., IV., VII., and X. of my
'Constellation Seasons,' fourth-magnitude stars, however, being omitted.


PLATES II., III., IV., and V., illustrating Chapters II., III., IV., and V.

Plates II. and IV. contain four star-maps. They not only serve to
indicate the configuration of certain important star-groups, but they
illustrate the construction of maps, such as the observer should make
for himself when he wishes to obtain an accurate knowledge of particular
regions of the sky. They are all made to one scale, and on the conical
projection--the simplest and best of all projections for maps of this
sort. The way in which the meridians and parallels for this projection
are laid down is described in my 'Handbook of the Stars.' With a little
practice a few minutes will suffice for sweeping out the equidistant
circular arcs which mark the parallels and ruling in the straight
meridians.

The dotted line across three of the maps represents a portion of the