Signed by Erasmus Habermel
Late 16th century; German
Gilt copper and brass; 175 x 175 mm
The upper face has a horizontal string-gnomon dial, the string supported by a sprung folding upright, shaped to accommodate a plumb-line (missing). Approximate latitude 48 degrees. The edge of the square plate is divided to hours, with Roman numerals, sub-divided to half and to quarter hours. Within the square is a series of concentric circles: each hour is divided by a diagonal line to 5 minutes, marked by concentric circles, and sub-divided to single minutes, marked by dots, numbered by 5. A central glazed compass, with a diagonal bar for the lower end of the string, blued steel magnetic needle, silvered plate with cardinal points marked 'ME', 'OC', 'SE', 'OR', target offset to the east for variation. The corners have foliate decoration typical of Habermel.
Oppose the folding upright is a volvelle for converting between 12 and 24-hour systems, with the inscription arranged in a spiral: 'HOAR 24 TRADVCTA AD HORAM ORTVS SOLIS INDICAT HORAS ITALICAS & NORICAS DIVRNAS: AD OCCASVM BOHEMICAS & NORIBERGENSES NOCTVRNAS: AD MERIDIEM VERO ASTRONOMICAS'
The dial itself carries the inscription: 'OMNIA PERVERTIT S?CLI MVTABILIS ORDO'.
Signed on the rim: 'Erasmus Habermel Fec:'.
Underneath are four ball feet. The plate carries a zodiacal calendar, with engraved zodiac signs, month and zodiac names in Latin, the former divided to single days, the latter to single degrees, the first point of Aries is at 201/2 March. Two circular scales give times in hours and minutes of sunrise throughout the year in ordinary and Italian hours. Foliate decoration in the corners and on the silvered base of the compass plate.
Museum of the History of Science, Oxford
Inventory number 39980
© Museum of the History of Science, Oxford. All rights reserved. Information and images provided here may not be reproduced in any form or by any means without the prior written permission of the museum.
Basic URL: http://www.mhs.ox.ac.uk/epact/catalogue.php?ENumber=98313