In chapter 11, “Of writing by invented characters,” he says: “There have been some other inventions of writing by points, or lines, or figures.”

Chapter 13 is, “concerning an universal character that may be legible to all nations and languages,” concluding with observations on “The benefit and possibility of this.”

In chapter 17, we are told “of secret and swift informations by the species of sound.” Among others he names “Bells,” as a species which “may be a sufficient means, whereby to communicate the thoughts;” and in chapter 18, he treats “concerning a language that may consist only of tunes and musical notes, without any articulate sound.” And lastly, in chapter 20, we have “Of informations by significatory fires and smokes.”

Among the “variations” the sense of Seeing may be employed, as proposed by Sir Hugh Plat in his “Jewel House of Art and Nature,” 1653, in which he describes “How to speak by signs only without uttering of any word”—using the fingers and motions with them and the hands, which he calls a “conceited alphabet.”—Page 38.

Those who are curious in such matters, may see more at large in Dr. W. Hooper’s Rational Recreations, ed. 1794, 8vo. different methods of writing in cipher, commencing at p. 143, of 1st Vol.—thus:—

To communicate intelligence by a pack of piquet cards.—The musical dial.—The corresponding spaces.—The musical cipher.—Rules for deciphering.—Example of a cipher written in arbitrary characters, and the words separate from each other.—Visual correspondence; and, Correspondence by bells.

[44.]

To make a Key of a Chamber door, which to your sight hath its Wards and Rose-pipe but Paper-thick, and yet at pleasure in a minute of an hour shall become a perfect Pistol, capable to shoot through a Brest-plate commonly of Carabine-proof, with Prime, Powder and Firelock, undiscoverable in a strangers hand.

[A Key-Pistol.] This mere piece of ingenuity, so pleasing to certain mechanics in working out mechanical trinkets, might be effected by causing the removal of the key handle to expose a sufficiently strong pistol barrel, while the “rose pipe but paper thick” would answer to receive, and perform the office of retaining the key handle securely, by which to hold it while firing this key-pistol. The next part of the contrivance would be, to make the “wards” serve to conceal the pistol pan, cock, &c. The description is well calculated to mislead the reader, under the impression that the barrel itself is “but paper-thick.”

45.