A FINE MID-16TH-CENTURY GERMAN GILT-BRASS ASTRONOMICAL COMPENDIUM,
signed and dated CHRISTOFFERVS SCHISLER ME FECIT AVGVSTE ANNO DOMINI 1556
This compendium is made with a central section, containing the magnetic compass, with two hinged plates, above and below. On the outside of the top plate is a nocturnal, marked with the months and two viewing slits to read the length of the night at the latitudes of 50° and 48°. The central hole is to view the Pole Star, and around the hole rotates the index arm, marked REGVLA HORE NOCTIS. Around the centre is inscribed POLVM ARTICVM VEL VRSA MAIOREM APLICANDVM. At the hours between 4a.m. and 8p.m. are knobs for identifying the hour indicated by the index by the fingers at night.
The underside of the top has a band inscribed with the days of the Moon's age to 29½ (new Moon), followed by a band with twice 12 hours marked in Roman numerals, and finally, there is a volvelle with twice 12 hours marked in Roman numerals. Cut in the volvelle is a lunar aspectarium. At the centre is a small hole for the nocturnal and for the insertion of a windvane, and around this are marked eleven wind directions (North is absent because of the lunar phase aperture): AQVILO, CECIAS, SVBSOLAN, VOLTVRNVS, EVRO AVST, AVSTER, LIBONATVS, APHRICVS, ZEPHIRVS, CHORVS, CIRCIVS.
The upper part of the central section has a horizontal dial, with a gnomon adjustable for the latitude, and five chapter rings for the latitudes 42°, 45°, 48°, 51°, 54°. At the centre is a hole through which the magnetic compass protrudes. The under part has a table for the latitudes of thirty towns in Europe.
The lower plate has on the inside the magnetic compass, which has a rotatable collar and a small index, named REGVLA. The signature is in a surrounding ring, and in around the edge is a degree scale, 0-90° in quadrants.
On the outside (the bottom of the instrument), is marked out with a planetary hour diagram for the twelve hours of the day and twelve hours of the night. This diagram is labelled instrvmentvm hore planetarvm. The lines between sunrise and sunset are labelled HORIZON ORTVS and HORIZON OCCASVS. A solar declination scale is on the central line, the parts of the year shown by the symbols of the Zodiac. An outermost ring is divided into 24 mean hours -- 6.8 x 7cm. (2 5/8 x 2¾in.)
Ex Rothschild Collection, 8 July 1999, Lot 160, inv. no. AR2640