12
The Trech Periscope
The trench Periscope was used for lookn out over the front of trenches to see other trenches without getting shot by enemy snipers. They were very useful and some manufacturers made and used larger periscopes like a german optical manufactuer that made a telescopic periscope with powerful magnifying lense it could be extended to 25 meters or completely collapsed and mounted on a compact field carriage for transport.
Early trench periscopes were made by installing to mirrors at 45- degree angles at either end of end of a long box or tube made of glass metal and wood until they got more advanced. During the winter of 1914-1915 soldiers on the front lines used these improvised box periscopes also known as hyposcopes. Most measured between 30 centimetres and 100 centimetres in length. in Early 1915 commercial manufacture of box type trench periscopes began in the united kingdom. However demand exceeded supply until 1916. To make up for the shortfall in commercial supply. British army workshops behind the front lines started to manufacture trench periscopes in mid 1916.