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Isaac Habrecht 3 1/4" Equinoctial Ring Dial
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50041
A Rare 17th Century, Silver Equinoctial Ring Dial:
French ca. 1667. Signed in script: “A la Just Paix Isaac Habrecht” on the meridian ring. Translation means: “Has the just piece Isaac Habrecht.” A very early example of this type of equinoctial ring dial made entirely of silver. Silver was a very expensive material used to manufacture this type of dial in the mid 17th century, and very few are known to exist, or have survived. “Isaac Habrecht” refers to Isaac Habrecht III (1611-1686) (1), who was the son of Isaac Habrecht II (1589-1633), a Strasbourg physician, mathematician and astronomer. He was the grandson of Isaac Habrecht I (1544-1620) the celebrated maker of the astronomical clock at the Strasbourg Cathedral which was completed in 1574. Isaac Habrecht I (Fig. 1) and his brother Josias immigrated to Strasbourg, France from Schaffhausen, Switzerland in ca. 1550, and formed the rudiments for this well know family of horologists (2).
Isaac Habrecht III, known as the “Horloger a Strasbourg ” (2) was known to have produced celestial globes with clockwork. An excellent example (GLB0174) is currently on display at the National Maritime Museum (3) in Greenwich, London. He was not known to have produced many other types of instruments. This present, early dial is attributed to his workshop because the basic design concept of the folding Universal Equinoctial Ring Sundial was not developed until ca. 1633 by Elias Allen (4), precluding his father and grandfather as possible makers.
The dial measures 7.9 cm (3.25 in) in diameter X 5 mm thick, with a 2 cm silver suspension ring. Weight is 120.5 g (4.25 oz). The equinoctial ring is laid out for a 24 hour calibration, i.e. 2 sets of I-XII, with the number four indicated as “IIII”. The horological circle is further subdivided into one-half hour increments which continue on the inside edge. Enough spacing is present to easily allow estimation of time to within 15 min intervals. The Meridian ring is engraved with a latitude scale of 0-90° in 5° increments, which are further subdivided into 1° increments. This indicates the dial was manufactured for use within the latitudes of Western Europe; i.e. France.
The bridge, with sliding pin-hole gnomon, has decorative end engravings and pivots within the horological sphere. On one side there is a beautifully engraved zodiacal symbol scale. On the other side, a date scale represented by the first letter of each month. This scale is subdivided into two week increments. No indication for a spring or fall equinox is given. Condition: The dial is in fine condition with light wear and no damage. There is typical silver oxidation with blue and purple hues, darker in the recessed areas, giving fabulous visual appeal. A quite rare and desirable 17th century horological dial made entirely of silver. Bibliography:
1. History database at the Adler Planetarium; i.e. [historydb.adlerplanitarium.org].
2. Ungerer, Theodore (1925) Edition des Archives Alsaciennes d’Histoire de l’Art, Strasbourg 1925.
3. Dekker, Elly (1999) Globes at Greenwich [019 8565593]. A catalogue of the Globes and Armillary Spheres in the National Maritime Museum.
4. Hester Higton (2001) Sundials, An Illustrated History of Portable Dials. ISBN [0 85667 523 7].
A rare rendition of Isaac Habrecht I. No paintings or sketches of his son or grandson are known to exist.
French ca. 1667. Signed in script: “A la Just Paix Isaac Habrecht” on the meridian ring. Translation means: “Has the just piece Isaac Habrecht.” A very early example of this type of equinoctial ring dial made entirely of silver. Silver was a very expensive material used to manufacture this type of dial in the mid 17th century, and very few are known to exist, or have survived. “Isaac Habrecht” refers to Isaac Habrecht III (1611-1686) (1), who was the son of Isaac Habrecht II (1589-1633), a Strasbourg physician, mathematician and astronomer. He was the grandson of Isaac Habrecht I (1544-1620) the celebrated maker of the astronomical clock at the Strasbourg Cathedral which was completed in 1574. Isaac Habrecht I (Fig. 1) and his brother Josias immigrated to Strasbourg, France from Schaffhausen, Switzerland in ca. 1550, and formed the rudiments for this well know family of horologists (2).
Isaac Habrecht III, known as the “Horloger a Strasbourg ” (2) was known to have produced celestial globes with clockwork. An excellent example (GLB0174) is currently on display at the National Maritime Museum (3) in Greenwich, London. He was not known to have produced many other types of instruments. This present, early dial is attributed to his workshop because the basic design concept of the folding Universal Equinoctial Ring Sundial was not developed until ca. 1633 by Elias Allen (4), precluding his father and grandfather as possible makers.
The dial measures 7.9 cm (3.25 in) in diameter X 5 mm thick, with a 2 cm silver suspension ring. Weight is 120.5 g (4.25 oz). The equinoctial ring is laid out for a 24 hour calibration, i.e. 2 sets of I-XII, with the number four indicated as “IIII”. The horological circle is further subdivided into one-half hour increments which continue on the inside edge. Enough spacing is present to easily allow estimation of time to within 15 min intervals. The Meridian ring is engraved with a latitude scale of 0-90° in 5° increments, which are further subdivided into 1° increments. This indicates the dial was manufactured for use within the latitudes of Western Europe; i.e. France.
The bridge, with sliding pin-hole gnomon, has decorative end engravings and pivots within the horological sphere. On one side there is a beautifully engraved zodiacal symbol scale. On the other side, a date scale represented by the first letter of each month. This scale is subdivided into two week increments. No indication for a spring or fall equinox is given. Condition: The dial is in fine condition with light wear and no damage. There is typical silver oxidation with blue and purple hues, darker in the recessed areas, giving fabulous visual appeal. A quite rare and desirable 17th century horological dial made entirely of silver. Bibliography:
1. History database at the Adler Planetarium; i.e. [historydb.adlerplanitarium.org].
2. Ungerer, Theodore (1925) Edition des Archives Alsaciennes d’Histoire de l’Art, Strasbourg 1925.
3. Dekker, Elly (1999) Globes at Greenwich [019 8565593]. A catalogue of the Globes and Armillary Spheres in the National Maritime Museum.
4. Hester Higton (2001) Sundials, An Illustrated History of Portable Dials. ISBN [0 85667 523 7].
A rare rendition of Isaac Habrecht I. No paintings or sketches of his son or grandson are known to exist.
Fig. 1: Isaac Habrecht I, 1608.
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