👉 In mathematics, a periscaper is a type of object that can be used to measure or locate an area. These objects are commonly used in navigation and mapping applications, such as GPS systems. The term "periscaper" was first introduced by the Swiss mathematician Johann Heinrich Lambert in his 1820 paper "Sur une nouvelle méthode de déterminer la longueur d'un arc", which is now known as Lambert's method. This method involves using a device that can