RECORD: Darwin, C. R. n.d. note on the use of the micrometer. Whipple-Wh.3788.3. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed and edited by John van Wyhe 2009. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the the Whipple Museum of the History of Science, University of Cambridge and William Huxley Darwin. With thanks to Tim Eggington.
An eye-piece micrometer is a glass disc that fits in the eye-piece of a microscope in order to measure the size of objects.
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Micrometer
When 2 inch object glass is used pull out tube 2 inches & use either 1/100 or 1/200 of inch micrometer. It makes no difference which of its 2 eye-pieces are used
If 2/3 inch object glass is used pull out tube 3 1/2 / 10' of an inch.—
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 5 December, 2022