"Straught up!"
"Right. Where is nine o'clock?"
"Over tae the left."
"Very good. And so on with all the other hours. Now, supposing I were to say, End of mansion-house—six o'clock—white gate—you would carry your eye straight downward, through the garden, until it encountered the gate. I would thus have enabled you to recognise a very small object in a wide landscape in the quickest possible time. See the idea?"
"Yes, sirr."
"All right. Now for our fold in the ground. End of mansion-house—eight o'clock—got that?"
There is an interested murmur of assent.
"That gives you the direction from the house. Now for the distance! End of mansion-house—eight o 'clock—two finger-breadths—what does that give you, Lance-Corporal Ness?"
"The corrner of a field, sirr."
"Right. This is our field. We have picked it correctly out of about twenty fields, you see. Corner of field. In the middle of the field, a fold in the ground. At nine hundred—at the fold in the ground—five rounds—fire! You see the idea now?"