ays in a mirror you get two more ways.
Now, all the other eleven solutions are non-symmetrical, and therefore
each of them may be presented in eight ways by these reversals and
reflections. It will thus be seen why the twelve fundamentally different
solutions produce only ninety-two arrangements, as I have said, and not
ninety-six, as would happen if all twelve were non-symmetrical. It is
well to have a clear understanding on the matter of reversals and
reflections when dealing with puzzles on the chessboard.

Can the reader place the eight queens on the board so that no queen
shall attack another and so that no three queens shall be in a straight
line in any oblique direction? Another glance at the diagram will show
that this arrangement will not answer the conditions, for in the two
directions indicated by the dotted lines there are three queens in a
straight line. There is only one of the twelve fundamental ways that
will solve the puzzle. Can you find it?

301.--THE EIGHT STARS.

[Illustration:

+---+---+---+---+---+---+---+---+
|///| | | | | | |///|
+---+---+---+---+---+---+---+---+
| |///| | | | |///| * |
+---+---+---+---+---+---+---+---+
| | |///| | |///| | |
+---+---+---+---+---+---+---+---+
| | | |///|///| | | |
+---+---+---+---+---+---+---+---+
| | | |///|///| | | |
+---+---+---+---+---+---+---+---+
| | |///| | |///| | |
+---+---+---+---+---+---+---+---+
| |///| | | | |///| |
+---+---+---+---+---+---+---+---+
|///| | | | | | |///|
+---+---+---+---+---+---+---+---+

]

The puzzle in this case is to place eight stars in the diagram so that
no star shall be in line with another star horizontally, vertically, or
diagonally. One star is already placed, and that must not be moved, so
there are only seven for the reader now to place. But you must not place
a star on any one of the shaded squares. There is only one way of
solving this little puzzle.

302.--A PROBLEM IN MOSAICS.

The art of producing pictures or designs by means of joining together
pieces of hard substances, either naturally or artificially coloured, is
of very great antiquity. It was certainly known in the time of the
Pharaohs, and we find a reference in the Book of Esther to "a pavement
of red, and blue, and white, and black marble." Some of this ancient
work that has c