“I believe I have it at last,” he said quietly but with ill-concealed eagerness in his tones. “Those irregular lines in certain of the circles are broken bits of the coast line. See here, those two between 8 and U are surely the Wash, and that below H is Flamborough Head. Let’s see if we can locate correspondingly shaped outlines on the atlas, and fill in between those on the photograph with pencil.”
A few seconds’ examination only were needed. Opposite, but slightly above the projection which French suggested as Flamborough Head was an angled line between GU and 31 which all three simultaneously pronounced St. Bee’s Head. Short double lines on each side of 24 showed two parts of the estuary of the Severn, and projections along the bottom near X and 27 were evidently St. Alban’s Head and Selsey Bill.
That they were on the right track there could now no longer be any doubt, and they set themselves with renewed energy to the problem still remaining—the meaning of the circles and the numbers they contained.
“We can’t locate the blessed things this way,” French pointed out. “We’ll have to rule squares on the atlas to correspond. Then we can pencil in the coast line accurately, and see just where the circles lie.”
For a time measuring and the drawing of lines were the order of the day. And then at last the positions of the circles were located. They were all drawn round towns.
“Towns!” Price exclaimed. “Guess we’re getting on.”
“Towns!” Cheyne echoed in his turn. “Then you must have been right, Inspector, about those letters being merely a blind.”
“I think so,” French admitted. “Look at it in this way. If only the towns and coast were marked, the shape of England would show too clearly. But adding those letter circles disguises the thing—prevents the shape becoming apparent. Now, I may be wrong, but I am beginning to question very much if this map has anything to do with indicating a position—I mean directly. I am beginning to think it is merely a cipher. Let us test this at all events. Let us write down the names of the towns in the order of the numbers and see if that gives us anything.”
He took a sheet of paper, while Price found No. 1 on the photograph and Cheyne identified its position with that of a town on the atlas map.
“No. 1,” said Cheyne, “is Salisbury.”