Reflections in History: The Periscope
From the creative mind of H.G. Wells to the Seawolf-Class vessels of the modern American navy, submarines are one of the most unique and carefully-engineered monstrosities to ever come out of the human mind. But as avid-lovers of anything mirror related, Superior Mirror’s absolutely favorite part of the submarine is (you guessed it) the periscope. Besides their obviously-awesome technique for letting the crew peek out of the water while still beneath the surface periscopes are one of the best ways mankind has cleverly used mirrors to solve otherwise vexing problems. So today get ready, because we’re going to visit that awesome tool of exploration and see what makes it tick! Down periscope!
Peering through the Pipe
Most people know what a periscope is used for, but not the science behind it; the basic concept is positioning mirrors at opposite ends of a container, each turned at 45 degree angles. Since the reflective surfaces are parallel to each other, it allows the viewer to see objects that are outside of their line of sight in a discrete and relatively simple manner.
Credit for the periscope in the military is spread evenly across three individuals: Hippolyte Marie-Davy, Simon Lake and Sir Howard Grubb. Marie-Davy is credited as the actual inventor, developing a prototype in 1854 using reflecting mirrors set into an elongated waterproof tube. But it wasn’t until the early 1900’s when submarines were developed that Simon Lake thought of using it to see above the surface of the water while the vessel was submerged. The periscope received its final upgrade during the First World War, when trench warfare made the periscope a military asset and prompted Sir Howard Grubb to develop a version that was lightweight, portable, collapsible, and easily replicated. For the next 50 years, periscopes become a standard for military infantry training, tanks, and of course submarines without any significant alterations.
Due to overall military advancement in technology, the periscope is quickly becoming obsolete. Though modern periscopes incorporate lenses and filters for magnification and use in bad weather, using reflecting mirrors in naval warfare cannot compete with satellite imagery, advanced radar and underwater drones. Indeed the new Virginia-Class submarines which began service in 2000 utilize what is known as the Photonics Mast Program (PMP), a s system of electronic imaging sensors that are raised above the waterline. Unlike a periscope, the opening in the hull necessary for the image sensor cables require an opening 1/10th the size of their predecessor, making it both safer and easier to image the surface from below.
Everyone at Superior Mirror knows it’s always sad when a classic dies, and the periscope is no exception. But there’s no denying our history, and it is quite clear that no matter where technology takes us, we’ll always know that mirrors helped make it happen.