Dominion Astrophysical Observatory, Victoria, B. C

S. Plaskett J.

Description

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The order for the large disc for the 72-inch mirror and for an auxiliary flat of 55 inches diameter for testing the 72-inch was given to the St. Cobain Glass Works of Paris by the Jno. A. Brashear Co. As soon as the contract was awarded. The 72-inch disc was cast and annealed by June 1914 and was fortunately shipped at once without waiting for the 55-inch disc. It left Antwerp only about a week before war was declared and it was only by this small margin that Canada now has a 72-inch telescope. Grinding and polishing were at once begun but the lack of the large flat and other difficulties delayed the completion and it was not until April 1918, about a year and a half after the completion of the mounting, that the figuring was finally completed and the telescope ready for work. Nevertheless, for an undertaking of such magnitude the work was completed in record time, four and a half years after the awarding of the contracts.

Sujets

• Sciences et techniques
• Astronomy

Informations

• Publié par: Forgotten Books
• Date de parution: 27 novembre 2019
• Nombre de lectures: 0
• EAN13: 9780243648924
• Langue: English
• Poids de l'ouvrage: 2 Mo

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