There the senior professor of geology had sat up with it far into the night in a darkened laboratory, with little blue flames playing underneath crucibles, as in a magician's cavern, and with the door locked.

And as each sample that he tested was set aside and tied in a cardboard box by itself, he labelled it "aur.

p.

75," and the pen shook in his hand as he marked it.

For to professors of geology those symbols mean "this is seventy-five per cent pure gold." So it was no wonder that the senior professor of geology working far into the night among the blue flames shook with excitement; not, of course, for the gold's sake as money (he had no time to think of that), but because if this thing was true it meant that an auriferous vein had been found in what was Devonian rock of the post-tertiary stratification, and if that was so it upset enough geology to spoil a textbook.