国外经典数据压缩文献
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.
