Who Invented the Periscope?
In 1854, Frenchman Hippolyte Marie-Davey invented the first naval periscope, which was a sight tube made of two mirrors at 45-degree angles. In the 1880s, other periscopes were created, but these designs, including Marie-Davey's, were still primitive in development and not entirely useful.
Thomas H. Doughty of the United States Navy invented a prismatic periscope, which was used in the American Civil War. In 1902, Simon Lake, a submarine engineer, created a more effective, collapsible omniscope with eight prisms for all-around, rotating viewpoints. This was helpful for viewing the water while the submarine moved at a lower speed. Improvements to Lake's omniscope included a double tube, so that it could withstand more pressure and speed.