A few days later I called upon Goldberg. His house was at the end of that long row of gloomy second-rate-looking residences, with deep basements and flights of stone steps leading to the front doors, which line one side of Hatton Garden. There was nothing in the exterior to attract the attention of any enterprising burglar, with the exception, perhaps, of the iron bars which protected the windows in the area, and even the shining brass plate bore simply the name, “F. Goldberg,” without any indication of his business. Inside, in the room used as office, the feature one would have expected to find—namely, a great green-painted iron safe with enormous handles and hinges—was absent. The room was nothing more than a comfortable library with well-filled bookcases around the walls.

When I entered Goldberg was busy writing letters. Rising, he grasped my hand, and, greeting me warmly, bade me be seated in the client’s chair.

“You would like to see your blind protégé at work, eh?” he said, when we had been chatting some time. “Well, you shall. He’s a marvellous workman. See, here’s a stone he finished this morning;” and taking from a drawer in his writing-table a tiny round cardboard box, he removed the lid and handed it to me. Lying in its bed of pink cotton wool was an enormous yellow diamond, which flashed and gleamed in the ray of sunlight that strayed into the room.

“How much is it worth?” I inquired.

“My price is a thousand pounds,” he replied. “That particular one, however, has been ordered by a jeweller, and is to form the centre of an ornament which, in a few weeks’ time, will be presented by a bridegroom to his bride.”

“I should like to see Karelin at work,” I said.

My friend acquiesced willingly, and took me upstairs to a small back room, where the old man was seated. He was busily engaged “cleaving” a rough diamond by means of another sharp-edged gem. In order that he should not be aware of my presence, I did not speak. His master addressed some words to him regarding his work, which the old lapidary answered without turning his sightless eyes towards us. The careful and accurate manner in which he worked was little short of marvellous, for he stopped every few moments to feel with the tip of his forefinger the precise dimensions of the incision he was making in the stone.

My object in seeing him at work was twofold. The first was to watch the movement of his face, but I found that it wore the blank, expressionless look of a blind man. The second was to make an investigation. His coat was hanging upon a nail behind the door, and holding up my finger to my friend as an indication of secrecy, I crossed noiselessly to the garment, and placing my hand in the breast-pocket, abstracted its contents.

A momentary glance was sufficient to detect the object which I sought, for, folded in half and lying among a number of letters and bills, was the missing copy of the revolutionary pamphlet.