“That’s a toppin’ notion,” echoed Bob; “let’s raid ‘old Beetle’s’ museum and dig out the posts.”

So Captain Richard Nevin, R.E., and Second-Lieutenant Robert Simpson, R.G.A., took the affair into their own hands.

Having seen the same forces cooperating on previous occasions, I determined to keep clear of them.  Besides, I am only “old Beetle.”

They found the posts in the tool-shed, and, borne upon the initial enthusiasm of their venture, began to sink a sort of winze on each side of the lawn.  Up to this point they were perfectly amicable.

Then Nevin, who is a thoughtful person, said suddenly, “I suppose you made quite sure that the line of these posts will cross the centre of the court?” And then, before Bob could retort, added, “Of course you ought to have made absolutely certain of that.  As it is we had better leave this and find the corner irons.”

Corner irons that have remained undisturbed for some twenty-four months have a way of concealing themselves.  At the end of ten minutes the seekers began to show signs of impatience.  Such terms as “angles,” “bases,” “centres,” interspersed with “futilass,” “sodamsure,” “knowseverything” were cast upon a hazardous breeze.

Eventually they found one of the angles.  To the ordinary layman this would have meant the beginning of the end.  But Captain Richard Nevin and Second-Lieutenant Robert Simpson are made of different stuff.  They scorn the easy path.  They have stores of deep knowledge to draw upon which place their calculations beyond the ken of ordinary mortals.  After they had made a searching examination of the exhumed angle, Bob pulled out a pencil, prostrated himself behind it and then proceeded to gaze ecstatically over the top.

I moved my chair slightly south, and pretended to regard the apple-blossom, and when Nevin went into the house and brought out something which dimly resembled a ship’s sextant I had the extreme presence of mind not to make any inquiries.

Margery drifted up with a pink duster.

“What ever are they doing?” she asked.

“Hush!” I whispered; “Bob has just got the range of a supply train on the far side of the rockery, and if Nevin (Nevin is the Crown Prince of Wurtemberg) doesn’t get the longitude of Bob’s battery in the next minute or so it’s all up with his day’s rations.”

Suddenly Bob rose and made some calculations on an old envelope.

“That means three rounds battery fire,” I said, “and the Prince loses his lunch.”

Not satisfied with this success, Bob went indoors and looted the hall of three walking-sticks and Margery’s new sunshade.

“What’s he going to do now?” said Margery, with one eye on the sunshade.

He walked to the far end of the lawn and manoeuvred in a small circle.  “The water-jackets are boiling,” I replied, “and they’ve run out of cold water.  He’s divining with the sunshade.  Look!”