Inventory no. 37536 - Epact entry
Epact number: 45685
Signed by Philippe Danfrie
circa 1570; French
Brass; 200 mm in diameter
This armillary sphere has circles for the sun and the moon within the customary celestial sphere, and then a geographical sphere for the earth at the centre.
One curious feature is a very obvious mistake in the positioning of the zodiacal band representing the annual path of the sun on the celestial sphere. Aries, instead of being at the spring equinox, is at the summer solstice in the position that should be occupied by Cancer. Although the signs follow in their proper order, each is displaced by 90 degrees. From the engraving, the band appears to be original. Although there have been a number of repairs to this instrument, the error does has not been introduced in reassembling the rings, as the positions of the holes in the zodiacal band do not allow it to be fitted correctly.
Source museum: Museum of the History of Science, Oxford
Museum number: Inventory no. 37,536
The circular base has a central circular aperture, perhaps for a missing magnetic compass, and three male figures, possibly satyrs, lacking arms, supporting the base of the armillary sphere on their heads. From this base, three corresponding female figures rise to carry the horizon ring.
The horizon ring has eight points on the compass named in French, and the names of eight winds, the cardinal points also having representations of winds blowing from clouds, and a degree scale 0 (at the west) to 90 to 0 to 90 to 0, divided to 10, subdivided to 5 and to 1 with alternate hatching, numbered by 10. The ring is signed 'P. Danfrie. Fec.'
The meridian ring ('MERIDIANVS CIRCVILVS') sits in a support at the base and in slits in the horizon ring and has a degree scale for latitude, divided similarly to that on the horizon ring. A ring is fixed to the meridian ring at the north pole; it is divided into hours, 1 to 12 twice, with an index arm.
The meridian ring has pivots for the equatorial poles of the celestial sphere, which has solstitial ('COLVRVS SOLSTI') and equinoctial ('COLVRVS ÆQVINOCTORVM') meridian rings, equator ('ÆQVINOCTIAL'), tropics, arctic and antarctic circles (all the circles are named in Latin) and a zodiacal band. The meridian rings have scales divided similarly to those mentioned above, the equinoctial being numbered for declination, the solstitial for polar distance. The scale on the equator is for right ascension and is numbered 0 to 360 from the first point of Aries. The zodiacal band has names and representations of the signs and a 30-degree scale for each.
Pivots at the ecliptic poles carry two pairs of right-angled rings, one ('DEFERENS SOLEM') with a sun figure on its ecliptic ring, the other ('DEFERENS LVNEM') with the moon on an epicycle. Within this are pivoted two arms that extend to the equatorial poles and support a single ring within which is a geographical globe.