Technological Contributions
His interest in a variety of disciplines resulted in the technological advances of the following: agriculture, hydraulics, Military Engineering, instruments, and pharmacology. He published a book in 1606 on raising water by the force of the air. In 1608 he published a book on military engineering.
Additionally, della Porta perfected the camera obscura. In a later edition of his Natural Magic, della Porta described this device as having a convex lens. Though he was not the inventor, the popularity of this work helped spread knowledge of it. He compared the shape of the human eye to the lens in his camera obscura, and provided an easily understandable example of how light could bring images into the eye.
Della Porta also claimed to have invented the first telescope, but died while preparing the treatise (De telescopiis) in support of his claim. His efforts were also overshadowed by Galileo Galilei's improvement of the telescope in 1609, following its introduction in the Netherlands in 1608.
In the book, Porta also mentioned an imaginary device known as a sympathetic telegraph. The device consisted of two circular boxes, similar to compasses, each with a magnetic needle, supposed to be magnetized by the same lodestone. Each box was to be labeled with the 26 letters, instead of the usual directions. Porta assumed that this would 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, thereby helping in communicating.
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