with his oldest brother, Johann Christoph Bach (16711721), the organist at the Michaeliskirche in nearby Ohrdruf. There, he copied, studied and performed music, and apparently received valuable teaching from his brother, who instructed him on the clavichord. J.C. Bach exposed him to the works of the great South German composers of the day, such as Johann Pachelbel (under whom Johann Christoph had studied) and Johann Jakob Froberger; possibly to the music of North German composers; to Frenchmen, such as Jean-Baptiste Lully, Louis Marchand, Marin Marais; and to the Italian clavierist Girolamo Frescobaldi. The young Bach probably witnessed and assisted in the maintenance of the organ music. Bach's obituary indicates that he copied music out of Johann Christoph's scores, but his brother had apparently forbidden him to do so, possibly because scores were valuable and private commodities at the time.
the same point. One has only to find the center and everything is revealed at a glance. But in England the paths run criss-cross, and it is only by travelling down each one of them that one can build up a picture of the whole. De Tocqueville, in earlier work on the French Revolution, had explained how it was the printed word that, achieving cultural saturation in the eighteenth century, had homogenized the French nation. Frenchmen were the same kind of people from north to south. The typographic principles of uniformity, continuity, and lineality had overlaid the complexities of ancient feudal and oral society. The Revolution was carried out by the new literati and lawyers. In England, however, such was the power of the ancient oral traditions of common law, backed by the medieval institution of Parliament, that no uniformity or continuity of the new visual print culture could take complete hold
would dispense with secrecy altogether). Plaintext went in and plaintext came out, while anyone intercepting the message between the two endpoints would pick up nothing but a meaningless sequence of marks and spaces. Messages were enciphered, transmitted, received, and deciphered in a single operation—exactly as fast as a message in plain English. The advantage was not the mechanical enciphering and printing of the message. That had been accomplished as far back as the early 1870s by two Frenchmen, fimile Vinay and Joseph Gaussin—though not with the speed and ease of a typewriter keyboard. Rather it was the assimilation of encipherment into the overall communication process. Vernam created what came to be called "on-line encipherment" (because it was done directly on the open telegraph circuit) to distinguish it from the old, separate, off-line encipherment. He freed a fundamental process in cryptography from the shackles of time and error. He eliminated a
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