Accession No

5888

Brief Description

Rojas-type universal altitude dial, English or Spanish Netherlands, circa 1600

Origin

Spanish Netherlands or England [XRF analysis suggests continental brass so more likely the former]

Maker

Class

dials

Earliest Date

1600

Latest Date

1600

Inscription Date

Material

metal (brass, steel)

Dimensions

diameter: 60mm depth: 3mm

Special Collection

Provenance

Purchased from Sotheby's Olympia, 15/11/2002. Purchased by The Time Museum (Inventory 4050). Featured in Tesseract Catalogue 10, Spring 1985.

Inscription

Description Notes

Central brass disc rotatable within an outer ring. On the obverse the ring is engraved with a scale of degrees reading 0-90-0˚, numbered by groups of 10˚ in the upper two quadrants with 90˚ set below the suspension shackle for the instrument. The lower two quadrants are not numbered but are divided, like the upper quadrants, to 1˚. Within this rotates the central disc engraved with the an orthographic projection (after the type described by Juan de Rojas in 1550).
[NOTE: On 14/07/2015 XRF analysis was conducted on this instrument. Results and analysis are given in the ‘Notes’ field.]

References

Events