IND-IIA-F206-I05
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Pièce
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24-07-1922
Fait partie de Correspondence related to Nizamiah Observatory during 1917-1923
This letter is from John Evershed to Mr Bhaskaran about the instructions to pack the 15-inch lens in a large case. He also mentioned that he had put castor oil between the component lenses to keep them perfectly adjusted and saved about 8 percent of light otherwise lost by reflection.
Sans titre