Examlex
A small refracting "spyglass" telescope has an objective with a focal length of about 30 inches.The world's largest refracting telescope at Yerkes Observatory has an objective with a focal length of 63.5 feet.If they both use the same eyepiece,how much larger is the image with Yerkes than with the spyglass?
Serfdom Patent
A document or decree abolishing or altering the conditions of serfdom, a form of labor widely used in feudal systems where serfs were tied to and worked land owned by lords.
Joseph II
An Austrian Emperor known for his radical reforms, including measures to modernize and centralize the Habsburg Empire during his reign from 1765 to 1790.
Austrian Empire
A Central European multinational great power from 1804 to 1867, formed by the proclamation of the Habsburg emperor Francis II.
Enlightenment
An intellectual and philosophical movement in the 17th and 18th centuries emphasizing reason, individualism, and skepticism towards traditional doctrines.
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