Equatorial Instrument, French, 17th Century

Square base with pillar stand, horizontal circular plate, marked with winds, degrees and a zodiacal calendar. Pillar support for latitude degree circle, with index arm. Equatorial disc with degree scale, hours, shadow square, alidade whose pivot is adjustable on a radial slot with a scale 1 to 20. The underside of the equatorial disc has star names and right ascensions.