[_Reduced to a Point._] A man of the Marquis of Worcester’s ingenious cast of mind could readily have made up the entire “Century” out of these systems of alphabets and secret writing. He may have been acquainted with “Traicté des Chiffres, ou Secretes Manieres d’escrire, par Blaise de Vigenere, Bourbonnois.” 4to. Paris, 1586--now very scarce; but indeed there were many learned works on the subject, among which Trithemius’s “Libri Polygraphia VI,” 1600, was conspicuous. The long disuse of such methods of secretly conveying information, has reduced the cleverest of these systems of Cryptographia in public estimation. But, at the same time, these inventions were quite consistent with the early times in which the Marquis flourished. We shall see, in the next article, what probably illustrates this proposed use of a mere point or dot. 5. A way by a Circular motion, either along a Rule or Ring-wise, to vary any Alphabet, even this of Points, so that the self-same Point individually placed, without the least additional mark or variation of place, shall stand for all the 24. letters, and not for the same letter twice in ten sheets writing; yet as easily and certainly read and known, as if it stood but for one and the self-same letter constantly signified. [_Varied significantly to all the 24. letters._] This and the former article may certainly be taken in connection with each other; and the cipher engraved in No. 3, would seem to anticipate the present proposal of “a circular motion along a rule.” The “ring-wise” method may have been no more than a substitution for the octagon or any other figure. We fortunately find among the Harleian MSS. in the British Museum, No. 2428, a probable clue to this particular method of writing, which we shall give entire. It forms the first portion of the small oblong folio volume containing the Manuscript Century at the end, with many intervening blank pages between them. It is as follows:-- “_An explanation of the most exact and most compendious way of short writing. And an example given by way of Questions, and Resolves upon each significant point, proving how, and why, it stands for such and such a letter, in order Alphabetically placed in every page._ “A. Q. How is a point made to signifie an A. Resol. By being placed between the constant center of the square and the right side thereof in a streight line not touching it. [See diagram at the end]. It is proved by drawing a line from the said center towards, and not to touch the right side line, and then you will finde the line placed under an A of the Alphabett in each page. “B. Q. How is a point made to signifie a B. Res. By being placed between the center of the square, towards the right corner upper angle of the Octagon, or square devided in to eight Angles, not touching the line thereof.