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Inventory no. 48140 - Former Display Label

Italian NOCTURNAL and 'ROJAS' DIAL
1578

Gilt copper. Unsigned; inscribed, "ROMÆ a. 1578".

In the Zodiac/calendar scale of the nocturnal, {gamma} 0° = 10.5 March. The back of the nocturnal is shaped like the mater of an astrolabe; into the mater fits a reversible plate. On one side of this plate is engraved a 'Rojas' or 'Geminus' dial which is used in conjunction with a movable trigonus (with sights and a plumb-rule). On the other side of the plate are engraved a shadow-square, and a scale of degrees inscribed, "Ad Solis & stellar{u tilde} altitudines dimentiendas". The whole instrument is assembled by means of a wing-nut and a short threaded tube attached to the trigonus.

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Billmeir Collection

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