A late 16th-Century gilt-brass astronomical compendium,
unsigned and undated, possibly made in Spain -- 5.5 x 5.7 x 1.4cm. (2 1/8 x 2¼ x ½in.)
See Colour Illustration and Details
The instrument comprises three plates connected by long hinges to a rectangular frame. All surfaces are inscribed with words, numerals, or decoration. The top and bottom surfaces show considerable wear through having been kept in a pocket or bag.
A1: The top is pierced with a central, circular hole, 2.2cm. diameter, for viewing the magnetic compass in a lower section. Surrounding the hole are firstly, a band marked with the hours 1 to 12, and secondly, eight wind directions. These are named with attributes:
NORT Schon mittenacht
NORT OST Schon Raist
OST Schon Auffgang
SVD OST halb Schon
SVD Gerouctig mitag
SVD WEST Regen
WEST crueb nidergang
NORT WEST Schne Schaur
A2: The underside of top plate has a circular band with a moresque pattern; the corners are symetrically foliate.
B1: A hinged plate with a central hole, 2.9cm. diameter, with an added internal bevel. This is divided in 24 parts and above, on the plate, is a band numbering 24 hours labelled 1-12 twice. Crossing the hole and connecting the 6 o'clock positions is a bar with a central boss to insert a rod (missing) as the gnomon for the polar dial. The corners have a foliate decoration.
B2: The underside of the plate has attached on the right side a triangle of metal that is the base for a latitude strut, originally hinged to the triangle but now lost. The corners have a moresque design.
C1: Plate B is hinged to C, the top of the latter being designed as a horizontal dial marked in hours from 4am to 8pm. The necessary string gnomon (missing) locates from a small hole near the top centre of B2 to a point on the meridian line of the dial. The angle such a gnomon would make with the horizontal shows that the scale is intended for use at a latitude of about 48°. To the right is the latitude scale for use with the polar dial, the angle being set by the (missing) strut from plate B2. The scale runs from 0-60°.
In a cell at the middle of this plate is the magnetic compass. The compass box has a diameter of 2cm. There is a replacement domed glass cover with a machine-bevelled edge, and a corroded magnetic needle. Inside on the base is engraved a fiducial line to show the magnetic deviation, but the base has been turned so that the line is nearly East-West, which is meaningless. The form of this fiducial line, which replicates that of the needle, has a double curve at one end and an enlargement at the other; such a needle is normal for the later sixteenth and earlier seventeenth centuries. Between the compass and the chapter ring of the dial are moresque decorations.
C2: The underside of the compass box is engraved with a grotesque face merging into foliage. The surroundings are moresque.
This part of the compendium has a pair of strips, 0.7cm. wide, as part of the plate turned down to form right angles. Each with two screw holes, these strips attach in a rectangular cradle, so completing this part of the instrument. The four screws are missing. These will have dropped out over time, because the holes are quite short, and the tap to cut the thread was crude.
D1: The underside of the bottom plate is engraved in a four-fold floral pattern, with intermediate spaces hatched. The base for the clasp is riveted on the edge.
D2: The outside of the base is engraved with the names and latitudes of 24 towns, using the roman style of lettering. The whole surface shows considerable wear.
Brabannt . 51 Flanndres . 52
Lüzembürg . 53 Hollannd . 53
Seelandt . 53 Senaro . 50
Lisibona . 40 Pampelona . 45
Tolleta . 41 Vallonizia . 42
Barselona . 42 Granade . 38
Venise . 45 Milan . 45
Riga . 45 Paris . 48
Aügüsta . 48 Franckefort . 50
Norimberg . 49 Neapoli . 41
Londres . 54 Danemarche . 57
Büda . 47 Craconia . 50
Unusually, some of the locations are given through the name of the country and not that of the main town, thus: Luxembourg, Zeeland, Flanders, Holland, Denmark. Most of the latitudes are within a degree of modern values, and correspond to values found in lists of the late sixteenth and early seventeenth centuries. Notably adrift is 54° for London, when it is usually 52° in the period. The English craftsmen consistently gave 51½°. The predominant locations are in the Low Countries (6), the Iberian peninsula (6), Germany (4), and Italy (3). France has only Paris. The words on the top plate are in German. Much, perhaps all of the decoration was performed by etching.
With half of the listed towns being in the Low Countries and the Iberian peninsula, there is the suggestion that the compendium was made for one of these locations, possibly for a person trading between the two. The Southern Netherlands were ruled from Spain until the middle of the seventeenth century. Spain is also involved through the moresque decoration. This style was introduced in Europe by Moslem craftsmen from about 1530.
The lettering and decoration were produced by using a wax resist and etching. The brass will not have been of uniform quality, so differential etching will occur, giving rise to the pitting visible in the etched regions. The fire gilding was such that a thick layer of gold has been deposited. This has produced a surface unlike those of German, Flemish or English workshops of the period.