"What is it, Bill?" he said, as he shut the door of his study. "Ah!" said the Ancient, almost archly. "What do you think? The E-M-E-R-A-L-D! Eh? Eh?" He searched in his pocket. Humphrey de Bohun looked to see the jewel appear. Not at all. What appeared was a little round brass box, glass cased, and in it a trembling needle, that shook and shivered like a gossamer in a breeze. "Now, my dear Humphrey," said the Professor, "let us take two chairs; yes ... two chairs ... two chairs. Ah! yes, two chairs." They took two chairs. "And let me pull up this little table...." He had become almost businesslike, not to say sprightly, in concentrating upon what he was about to do. "Now, then; here we are, we two on these two chairs as it were, are we not? Yes! And here you see this little instrument, do you not? Yes! And do you know what it does ... what it is? What it is ...? It's a talcometer." "A what?" said the Home Secretary. "A talcometer," said Professor de Bohun, lying freely, and puffing slightly after the effort. "Now, Humphrey, I want you to watch something. To watch something, eh! Ah! yes. You have, I take it--ah!--or Marjorie has, or some one has a jewel--sure to have one. A diamond, say. Any stone--crystal. A stone, at any rate...." "I don't know," began Humphrey de Bohun, wondering what was to be. "Will this do?" he asked, leaning over towards his writing table and pulling off it the little crystal Chinese god which was used to weight down the papers which he had abandoned there so many days. Anything would do for the deceitful pedant. He nodded cheerfully. [Illustration: _Professor de Bohun explains to the head of the family his theory--or rather, certitude--upon the whereabouts of the Great Emerald._] "Yes," he said, "so long as it's crystal. Anything crystal. Crystal." Then he added, "Now, Humphrey, watch. Here," holding the little round brass disk with its trembling needle, "I have our talcometer. Now here," moving the Chinese god into line with the axis round which the tiny filament of metal trembled, "here we have this talcometer, _and_ the crystal. Eh! _And_ the crystal.... Now watch, Humphrey!" Holding the little round brass case with his left finger and thumb, he gradually with his right hand approached the heathenish idol, sliding the False God slowly along the polished table-top towards the instrument. It came closer and closer. It was at 9 inches, 6 inches, 3 inches, ... but there was as yet no apparent effect, when, suddenly, with the Pot-bellied Dwarf Deity at about 2 inches off, or a little less, the needle behaved like a pointer: it stood immovable, held rigidly by some strange force. The stud, dear friends, but how could Humphrey de Bohun know that? "There! You see that? See that? See that?" squeaked the Professor triumphantly. "Now I want you to test it for yourself. Move the little devil away! Move it yourself! Humphrey, move it yourself!"