Production year
1924
© Fonds historique / CNRS Images
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Centrographe Loker permettant de centrer les verres de lunettes, photographié le 14 mai 1924. Office national des recherches scientifiques et industrielles et des inventions. L'appareil dispose de deux verres : le premier est marqué d'une croix noire, le second d'une croix blanche. L'observateur doit amener le premier verre au-dessus de l'autre, de tel sorte que la croix noire se superpose à la blanche. L'opération effectuée, l'opticien ou l'oculiste obtient le centre correspondant au dioptre sphérique et les méridiens principaux du verre total.
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1924
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