“My dear fellow,” said the detective wearily, “no one travels with a typewriting machine unless that person is a typewriter. The girl, if you will notice, is now engaged in filling the leaves of her book with shorthand, therefore that proves her occupation. That she is secretary to a rich man is evidenced by the fact that she crossed in the _Servia_ first cabin, as you may see by glancing at the label on the case; that she came alone, which is to say her employer was not with her, is indicated by the typewriter being marked ‘Not Wanted,’ so it was put down into the hold. If a Chicago business man had been travelling with his secretary, the typewriter case would have been labelled instead, ‘Cabin, wanted,’ for a Chicago man of business would have to write some hundreds of letters, even on the ocean, to be ready for posting the moment he came ashore. The typewriter case is evidently new, and is stamped with the name and address of its sellers in Chicago. That she came by the Great Western is shown by the fact that ‘Chester’ appears on still another label. That she has special business in England we may well believe, otherwise she would have crossed on the French line direct from New York to Havre. So you see, my dear boy, these are all matters of observation, and quite patent to anyone who cares to use his eyes.” “Yes, it all seems very simple now that you have explained it,” growled Smith. “I should be a much more mysterious person than I am,” remarked the detective complacently, “if I did not explain so much. This explanation habit is becoming a vice with me, and I fear I must abandon it.” “I hope for my sake you won’t,” said Smith more good-naturedly, “for if left to myself I never could find out how you arrive at your wonderful conclusions. Do you expect the Austrian diamond mystery to prove difficult?” “Difficult? Oh, dear no! To tell the truth, I have solved it already, but in order to give the American a run for his money--and surely he ought not to object to that, because he is a millionaire who has made his fortune by giving other people runs for their money, being a railway man--I am now on my way to Vienna. If I solved the problem off-hand for him in London, he would have no more appreciation of my talent than you had a moment ago when I explained why I knew this French girl came from Chicago.” “You mustn’t mind that, Cadbury,” said Smith contritely. “I confess I was irritated for a moment because it all seemed so simple.” “My dear fellow, every puzzle in this world is simple except one, and that is to find any problem which is difficult.” “Then who stole the diamonds? The lieutenant?” The detective smiled and gazed upwards for a few tantalizing moments at the roof of the carriage.