If there is one of Samuel Pepys's many accomplishments for which posterity has reason to be particularly grateful, it is surely his knowledge of shorthand. With the exception of proper names and an occasional jumble of letters and languages (to which Pepys resorted for some of the more scandalous passages), the diary is written throughout in stenographic characters, and some of its most attractive qualities must be attributed to his proficiency in an art which, by enabling him to set down the details of many an episode before they faded from his memory, contributed to that racy spontaneity which is its greatest charm. Indeed, it is hardly too much to say that but for shorthand the diary as we know it could never have been written.

At least a score of different shorthand systems had been published in England before Pepys began to pen his famous self-revelation on i January 1660, three or four of them were at that time widely known and practised, and their adepts were so numerous as to excite the wonder and admiration of visitors from abroad. Perhaps the most popular of all these systems was that expounded in Thomas Shelton's Tachygraphy, first printed in 1635 at the Cambridge University Press. It was an improvement on an earlier presentation of the system which Shelton had launched nine years before, and at once achieved a great vogue.