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Porro was granted a patent for the invention of the direct-vision prism erecting systems in France and England in 1854. Porro received the patent for the deflection and erection by prisms, i.e. also the two erecting systems for telescopes, and also for his suggestion concerning a distance measuring instrument. A patent was also awarded for the projection of light into the ray path to simultaneously bring crosshairs into coincidence with an object and illuminate micrometers.
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| The construction of the prism erecting system. | Longue Vue Cornet from the collection of the Optical Museum in Oberkochen, Germany. |
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The monoculars produced by Porro, the ”Longue Vue Cornets” as they are also known, allow magnifications of 10x–12x. The second type of binoculars from Porro’s Paris workshop was the ”Lunette Napoleon III” with 10x magnification. In the ”Lunette” the entrance and exit faces of the prisms acted as the objective and the eyepiece. On February 22, 1855, Porro personally presented two telescopes of this kind to Emperor Napoleon III of France. | |
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