MSN home
Mail
My MSN
Sign in
encarta
greeting cards
more
Hotmail
Messenger
My MSN
MSN Directory
Air Tickets/Travel
Autos
Careers & Jobs
City Guides
Dating & Personals
Election 2008
Games
Green
Health & Fitness
Horoscopes
Lifestyle
Maps & Directions
Money
Movies
Music
News
Real Estate/Rentals
Shopping
Spaces
Sports
Tech & Gadgets
TV
Weather
White Pages
Yellow Pages
encarta
®
Home
Encyclopedia
Dictionary
Atlas
K-12 Success
College & Grad School
Adult Learning
Quizzes
More
Additional Reference Materials
Thesaurus
Translations
Multimedia
Other Resources
Education Resources
Math Help
Foreign Language Help
Project Planner
Scholarships & Financial Aid
Jobs & Internships
Online Degrees
Coffee Break
Ask Bill Nye the Science Guy
Top 10 Lists
Columns
On This Day
Encarta Products
Help
Related Items
from
Encarta
Optics
Light
applications
fiber optics
holography
lasers
microscopes
mirrors
periscopes
photography
spectroscopes
telescopes
three-dimensional images
atmospheric optics
lenses
mirrors
notable researchers
optical instruments and devices
optics of vision
perspective
pictures related to optics
properties of light
quotation
refractive index
units of measure
Periscope
Periscope
, optical instrument for conducting observations from a concealed or protected position. A simple periscope consists essentially of...
View article
MSN Privacy
Legal
Advertise
Newsletter
Worldwide
Feedback
Help
© 2008 Microsoft
Hotmail
Messenger
My MSN
MSN Directory
View article
