“The lens is spherically corrected for OO’, but the sinecondition is not fulfilled. Hens the different magnifications of a point O1 beyond the axis.” —Encyclopaedia Britannica, 1910
Encyclopaedia Britannica (11th ed., vol. 18) (New York, NY: The Encyclopaedia Britannica Company, 1910)
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1024×291, 28.1 KiB
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