674 OPTIC PROJECTION n. ARTIFICIAL CAMERA OBSCURA No one knows who first designedly arranged a darkened room with a white wall or screen oh one side, and on the other a small opening facing some object or scene that could be brightly illuminated. All we know is that the earliest accounts of the pictures in a dark place are in connection with the explanation of some other phenomenon, and not to show that such pictures were possible. It was also recognized in the first statements, as in the works of Aristotle and of Euclid, that as light rays extend in straight lines, that those from an object must cross in passing through a small hole, and hence the images beyond the hole in the dark place must be inverted, the top being below and the right being left. According to Wiedemann and Werner, the Arabians, Iban A1 Haitem (1039 A.D.), and Levi Ben Gersen (1321-1344), gave descriptions which clearly belong to the camera obscura. However, that may be, we have the illustrated manuscripts of Leonardo da Vinci, which not only describe the phenomena of the camera obscura, but give pictures which are unmistakable. The pic¬ tures and descriptions are in connection with his explanation of vision. As I Leonardo died in 1519, these manuscripts arc of an earlier date, probably before 1500 A.D. (See especially folio 8 of Ms. D.) Also in the accounts of eclipses, etc., of the astronomers Reinhold, Frisius and Moestlin, they very clearly describe and give figures of the arrangement of the dark room pictures (1540-1545) ; and in the quaint old volume of Cardanus (Dc Subtilitate, 1550), there is a very graphic description of the means of getting dark room pictures and of their appearance, jjîaptista Porta, in 1558, in his Natural Magic, also gives a good description. Porta is credited in the popular mind with the invention of the camera obscura, but as seen from the above, it is a natural thing, and man had got camera pictures by design before Porta was born. The Natural Magic of Porta was very popular in its day, and was translated from the Latin into most modem languages, hence it is intelligible that people thought him the inventor, as he gave credit to no one, and gave out that many of the things had never been known before. To credit him with the discovery of the marvelous things he describes would be like making the modem magazine writer the inventor or discoverer of the wonder¬ ful things he describes. In justice to Porta, it must be said that he states in the preface to his book that he has consulted all libraries, and has visited many skillful artisans to find out all the secrets. It may be stated in passing, that the name “Camera Obscura” was not used by Porta, nor the others mentioned alxive. They used expressions like these: cubiculum obscurum, eubiculum tenebricosum, conclave obscurum, locus obscurus, etc. The first occurrence of the name “Camera Obscura” found by us is in the Paralipomena of Kepler, (1604), p. 209 of the original, p. 261 in the Opera Omnia, vol. ii. Kepler also uses the expression, “camera clausa,” vol. ii, p. 160.