the postage paid, is called a stamp, and the postmarks or impressions indicating the names of towns are also called stamps.  Those postmarks or impressions had been the work of Bagwax’s life; but his zeal, his joy in his office, and the general energy of his disposition, had opened up to him also all the mysteries of the queen’s heads.  That stamp, that effigy, that twopenny queen’s-head, which by its presence on the corner of the envelope purported to have been the price of conveying the letter from Sydney to Nobble, on 10th May, 1873, had certainly been manufactured and sent out to the colony since that date!

There are signs invisible to ordinary eyes which are plain as the sun at noonday to the initiated.  It is so in all arts, in all sciences.  Bagwax was at once sure of his fact.  To his instructed gaze the little receipt for twopence was as clearly dated as though the figures were written on it.  And yet he had never looked at it before.  In the absorbing interest which the postmark had created,—­that fraudulent postmark as it certainly was,—­he had never condescended to examine the postage-stamp.  But now he saw and was certain.

If it was so,—­and he had no doubt,—­then would Caldigate surely be released.  It is hoped that the reader will follow the mind of Bagwax, which was in this matter very clear.  This envelope had been brought up at the trial as evidence that, on a certain day, Caldigate had written to the woman as his wife, and had sent the letter through the post-office.  For such sending the postage-stamp was necessary.  The postage-stamp had certainly been put on when the envelope was prepared for its intended purpose.  But if it could be proved by the stamp itself that it had not been in existence on the date impressed on the envelope, then the fraud would be quite apparent.  And if there had been such fraud, then would the testimony of all those four witnesses be crushed into arrant perjury.  They had produced the fraudulent document, and by it would be thoroughly condemned.  There could be no necessity for a journey to Sydney.

As it all became clear to his mind, he thumped his table partly in triumph,—­partly in despair.  ‘What’s the matter with you now?’ said Mr. Curlydown.  It was a quarter past four, and Curlydown had not completed his daily inspections.  Had Bagwax been doing his proper share of work, Curlydown would have already washed his hands and changed his coat, and have been ready to start for the 4.30 train.  As it was, he had an hour of labour before him, and would be unable to count the plums upon his wall, as was usual with him before dinner.

‘It becomes more wonderful every day,’ said Bagwax solemnly,—­almost awfully.

’It is very wonderful to me that a man should be able to sit so many hours looking at one dirty bit of paper.’

’Every moment that I pass with that envelope before my eyes I see the innocent husband in jail, and the poor afflicted wife weeping in her solitude.’