e other
diagonal will count as different, and similarly with other repetitions
obtained by turning the board round.

296.--THE FOUR LIONS.

The puzzle is to find in how many different ways the four lions may be
placed so that there shall never be more than one lion in any row or
column. Mere reversals and reflections will not count as different.
Thus, regarding the example given, if we place the lions in the other
diagonal, it will be considered the same arrangement. For if you hold
the second arrangement in front of a mirror or give it a quarter turn,
you merely get the first arrangement. It is a simple little puzzle, but
requires a certain amount of careful consideration.

[Illustration

+---+---+---+---+
| L | | | |
+---+---+---+---+
| | L | | |
+---+---+---+---+
| | | L | |
+---+---+---+---+
| | | | L |
+---+---+---+---+

]

297.--BISHOPS--UNGUARDED.

Place as few bishops as possible on an ordinary chessboard so that every
square of the board shall be either occupied or attacked. It will be
seen that the rook has more scope than the bishop: for wherever you
place the former, it will always attack fourteen other squares; whereas
the latter will attack seven, nine, eleven, or thirteen squares,
according to the position of the diagonal on which it is placed. And it
is well here to state that when we speak of "diagonals" in connection
with the chessboard, we do not limit ourselves to the two long diagonals
from corner to corner, but include all the shorter lines that are
parallel to these. To prevent misunderstanding on future occasions, it
will be well for the reader to note carefully this fact.

298.--BISHOPS--GUARDED.

Now, how many bishops are necessary in order that every square shall be
either occupied or attacked, and every bishop guarded by another bishop?
And how may they be placed?

299.--BISHOPS IN CONVOCATION.

[Illustration:

+---+---+---+---+---+---+---+---+
| B | B | B | B | B | B | B | B |
+---+---+---+---+---+---+---+---+
| | | | | | | | |
+---+---+---+---+---+---+---+---+
| | | | | | | | |
+---+---+---+---+---+---+---+---+
| | | | | | | | |
+---+---+---+---+---+---+---+---+
| | | | | | | | |
+---+---+---+---+---+---+---+---+
| | | | | | | | |
+---+---+---+---+---+---+---+---+