“You told me that you had been a mechanic in the works before your rheumatism got bad. Have you worked at any of those duplicators like what was packed in the crate?” “I worked at all kinds of erecting works—duplicators an’ files an’ indexes an’ addressing machines an’ all the rest o’ them. I knows them all.” “Good! Now I want you to come round to the store and show me the different parts of a duplicator.” Gurney led the way from the boiler-house. “Don’t switch on the light,” French directed. “I don’t want the windows to show lit up. I have a torch.” They passed through the packing-shed and into the completed-machine store adjoining. Here French called a halt. “Just let’s look at one of these duplicators again,” he said. “Suppose you wanted to take one of them to pieces, let me see how you would set about it. Should I be correct in saying that if five or six of the larger pieces were got rid of, all the rest could be carried in a handbag?” “That’s right, sir.” “Now show me the bins where these larger parts are stocked.” They passed on to the part store and across it to a line of bins labelled “Duplicators.” In the first bin were rows of leg castings. French ran his eye along them. “There must be fifty or sixty here,” he said, slowly. “Let’s see if that is a good guess.” On every bin was a stock card in a metal holder. French lifted down that in question. It was divided into three sets of columns, one set showing incomes, the second outgoes, and the third the existing stock. The date of each transaction was given, and for each entry the stock was adjusted. “Not such a bad guess,” French remarked, slowly, as he scrutinised the entries. “There are just fifty-four.” The card was large and was nearly full. French noticed that it went back for some weeks before the tragedy. He stood gazing at it in the light of his torch while a feeling of bitter disappointment grew in his mind. Then suddenly he thought he saw what he was looking for, and whipping out a lens, he examined one of the entries more closely. “Got it, by Jove! I’ve actually got it!” he thought, delightedly. His luck had held. One of the entries had been altered. A loop had been skilfully added to a six to make it an eight. The card showed that two castings had been taken out which either had never been taken out at all or, more probably, which had been taken out and afterwards replaced. Convinced that he had solved the last of his four test problems, French examined the cards of the other bins. In all of those referring to large parts he noticed the same peculiarity; the entries had been tampered with to show that one more duplicator had been sent out than really was the case. The cards for the small parts were unaltered and French could understand the reason. It was easier to get rid of the parts themselves than to falsify their records. The fraud was necessary only in the case of objects too big and heavy to carry away.