+---------------------------------------+
8 | | | | | | | | |
|---------------------------------------|
7 | | | | | | | | |
|---------------------------------------|
6 | | | | #K | | | | |
|---------------------------------------|
5 | | | | | | | | |
|---------------------------------------|
4 | | | | | | | | |
|---------------------------------------|
3 | | | ^K | | | | | ^Q |
|---------------------------------------|
2 | | | | | | | | |
|---------------------------------------|
1 | | | | | | | | |
+---------------------------------------+
a b c d e f g h

DIAGRAM 9.

How will White proceed in order to drive the King into a corner
and checkmate him there?

A direct onslaught with the Queen on e6 or d7 is clearly not
advisable as the Queen would not be protected on these squares,
so that the King could simply capture her. A long range attack
from h2, g3, d3 or h6 is not effective either as it would not
restrict the mobility of the King who could go to either d5 or e6