A
periscope, is a optical device for conducting observations from a concealed
or protected position. Simple periscopes consist of reflecting mirrors
and/or prisms at opposite ends of a tube container. The reflecting surfaces
are parallel to each other and at a 45° angle to the axis of the tube.
The Navy attributes the invention of the periscope (1902) to Simon Lake
and the perfection of the periscope to Sir Howard Grubb.
For all its innovations, USS Holland had at least one major flaw; lack of vision when submerged. The submarine had to broach the surface so the crew could look out through windows in the conning tower. Broaching deprived the Holland of one of the submarines greatest advantages stealth. Lack of vision when submerged was eventually corrected when Simon Lake used prisms and lenses to develop the omniscope, forerunner of the periscope. Sir Howard Grubb, designer of astronomical instruments, developed the modern periscope that was first used in Holland-designed British Royal Navy submarines. For more than 50 years, the periscope was the submarines only visual aid until underwater television was installed aboard the nuclear powered submarine USS Nautilus.
Sir Howard Grubb
Thomas Grubb (1800-1878) founded
a telescope making firm in Dublin. Sir Howard Grubb's father was noted
for inventing and constructing machinery for printing. In the early 1830s,
he made an observatory for his own use equipped with a 9-inch (23cm) telescope.
Thomas Grubb's youngest son Howard (1844-1931) joined the firm in 1865,
under his hand the company gained a reputation for the first-class Grubb
telescopes. During the First World War, demand was on Grubb's factory to
make gunsights and periscopes for the war effort and it was during those
years that Grubb perfected the periscope's design.
Photos
Click on thumbnails for larger
picture

French soldiers in Alsace using
trench periscope.
Trench periscope.
Related Information
Submarines
Build
your own Periscope
Many thanks to Rick Wattman of Periscope
Marketing Communications for his research.
Photos courtesy of "Photos
of the Great War" website
Interior of a British submarine
with periscope

