Introduction

• Published in: Data Compression pp. 1 - 15
• Format: Book Chapter
• Language: English
• Published: London Springer London 2007
• Subjects: Compression Method; Compression Ratio; Data Compression; Input Stream; Output Stream
• ISBN: 9781846286025; 1846286026
• DOI: 10.1007/978-1-84628-603-2_1

Giambattista della Porta, a Renaissance scientist sometimes known as the professor of secrets, was the author in 1558 of Magia Naturalis (Natural Magic), a book in which he discusses many subjects, including demonology, magnetism, and the camera obscura [della Porta 58]. The book became tremendously popular in the 16th century and went into more than 50 editions, in several languages beside Latin. The book mentions an imaginary device that has since become known as the “sympathetic telegraph.” This device was to have consisted of two circular boxes, similar to compasses, each with a magnetic needle. Each box was to be labeled with the 26 letters, instead of the usual directions, and the main point was that the two needles were supposed to be magnetized by the same lodestone. Porta assumed that this would somehow coordinate the needles such that when a letter was dialed in one box, the needle in the other box would swing to point to the same letter.