Translations:Adventist Youth Honors Answer Book/Health and Science/Optics/60/en

From Pathfinder Wiki
Revision as of 08:44, 9 January 2021 by FuzzyBot (talk | contribs) (Importing a new version from external source)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

A periscope may be used as a toy or for seeing over people's heads in a crowd. This form of periscope, with the addition of two simple lenses, was used for observation purposes in the trenches during World War I.