Details
A 19th-Century gilded copper reproduction horary quadrant in the style of Habermel, in a presumed original case.
Side 1. An horary quadrant with straight hour lines following Johannes Stöffler, Elvcidatio fabricæ vsvqve astrolabii (Oppenheim, 1512, and many later editions). The equal hours are from 5 in the morning to 7 in the evening. There are two sets, one for the summer period between the equinoxes, and one for the winter period. The solar declination scales are set to the right. At the apex the latitude is inscribed ELEVATIO POLI 47. The curve of the quadrant is divided in 90° both ways. This provided a reading of the latitude and the co-latitude. A small shadow square is at the apex, and there is a hole to attach the plumb-line. The plumb bob is present, ¾in. (1.9cm.) diameter, and this appears from its form and from an analysis of the gold plating, to be original. One edge carries a pair of sight vanes, with a double notch on the foresight and a single on the backsight. The foresight has a central pinhole, and rays from this are targeted onto a cross engraved on the backsight, which does not have a pinhole. This is a most unusual feature.
Side 2. The upper part is occupied by a triangle with concentric curves that is a conversion diagram between planetary and equal hours. The lower part is a table of the Governors of the Hours, labelled TABVLA PLANETARVM DIEI. Each of the twenty-four hours of the day were thought to be governed by a planet: for example, the first hour on a Sunday is governed by the Sun, the second by the Moon, the third by Mercury, and so on, hence the days of the week as we know them.
At the apex is inscribed Pragæ fecit 1597 Erasmus Habermel. All the engraving on this item is an attempt to imitate that produced by the Habermel workshop in Prague at the end of the sixteenth century. However, the result fails entirely when compared with genuine pieces. The lines composing the numbers and letters are too thin, the lower case letters are too square, the Zodiac symbols are an incompetent replica of Habermel's, and the shadowing and decoration are an inexpert imitation. Contrast with the Zodiac symbols on the Duke of Parma's astrolabe, sold in these rooms on 11 October 1995, p.15; also the planetary symbols on p.21, and other features in general.
The case is made of wood covered in dark brown calf with gold tooled borders. The inside is contoured to the shape of the instrument and is lined in pink chamois, now much faded. There is a neat depression for the plumb bob. It is possible that this case once held a quadrant now lost, which might, indeed, not have been a Habermel.
A chemical analysis of the instrument, the plumb bob, and the gold tooling, shows that the instrument has a composition different from the other two.
Dimensions: sides - 6.5/8in. (16.8cm.) long; degree scale - 6.1/8in. (15.5cm.) radius; the plate (uniform all over) - 6in. (0.17cm.) thick
See Colour Illustrations and Details
Side 1. An horary quadrant with straight hour lines following Johannes Stöffler, Elvcidatio fabricæ vsvqve astrolabii (Oppenheim, 1512, and many later editions). The equal hours are from 5 in the morning to 7 in the evening. There are two sets, one for the summer period between the equinoxes, and one for the winter period. The solar declination scales are set to the right. At the apex the latitude is inscribed ELEVATIO POLI 47. The curve of the quadrant is divided in 90° both ways. This provided a reading of the latitude and the co-latitude. A small shadow square is at the apex, and there is a hole to attach the plumb-line. The plumb bob is present, ¾in. (1.9cm.) diameter, and this appears from its form and from an analysis of the gold plating, to be original. One edge carries a pair of sight vanes, with a double notch on the foresight and a single on the backsight. The foresight has a central pinhole, and rays from this are targeted onto a cross engraved on the backsight, which does not have a pinhole. This is a most unusual feature.
Side 2. The upper part is occupied by a triangle with concentric curves that is a conversion diagram between planetary and equal hours. The lower part is a table of the Governors of the Hours, labelled TABVLA PLANETARVM DIEI. Each of the twenty-four hours of the day were thought to be governed by a planet: for example, the first hour on a Sunday is governed by the Sun, the second by the Moon, the third by Mercury, and so on, hence the days of the week as we know them.
At the apex is inscribed Pragæ fecit 1597 Erasmus Habermel. All the engraving on this item is an attempt to imitate that produced by the Habermel workshop in Prague at the end of the sixteenth century. However, the result fails entirely when compared with genuine pieces. The lines composing the numbers and letters are too thin, the lower case letters are too square, the Zodiac symbols are an incompetent replica of Habermel's, and the shadowing and decoration are an inexpert imitation. Contrast with the Zodiac symbols on the Duke of Parma's astrolabe, sold in these rooms on 11 October 1995, p.15; also the planetary symbols on p.21, and other features in general.
The case is made of wood covered in dark brown calf with gold tooled borders. The inside is contoured to the shape of the instrument and is lined in pink chamois, now much faded. There is a neat depression for the plumb bob. It is possible that this case once held a quadrant now lost, which might, indeed, not have been a Habermel.
A chemical analysis of the instrument, the plumb bob, and the gold tooling, shows that the instrument has a composition different from the other two.
Dimensions: sides - 6.5/8in. (16.8cm.) long; degree scale - 6.1/8in. (15.5cm.) radius; the plate (uniform all over) - 6in. (0.17cm.) thick
See Colour Illustrations and Details