- Museum number
Wall clock; cross-beat escapement; weight-driven; dials indicate the day, the date, age and phase of moon, sun's position in the zodiac, season and hours of light and darkness.
Gt wheel 90
2nd wheel 72/6
Escape wheel 26/6
See Clocks magazine May 1988 for full train count, breif description and diagrams by Richard Good.
- Production date
- Curator's comments
The following text is the entry for this object from the unpublished catalogue of pre-pendulum clocks by John Leopold, former Assistant Keeper of Horology at the Museum. This information is unedited and should be used accordingly.
WALLCLOCK WITH CROSSBEAT, BY (Wolfgang) Hager, Arnstadt; ca.1630.
Lloyd (1964) 81.
Maurice (1976) fig.725.
Edwardes (1977) pl.8-9.
Tait (1983) 50.
Tölke (1994) 21-24.
Oestmann (1999) 50-55.
Engraved in the middle of the dial, under the aperture for the moon: "Arn stad".
The steel case consists of the back, the top, the bottom and two side doors.
The back is a plain steel plate which carries the riveted spurs. The bottom is pinned to the back by two lugs; these lugs are the ends of two L-shaped pieces, which are riveted to the bottom to form fitments for the doors. Back and bottom are attached to the movement by the suspension-ring, which is screwed throught the back into the rear bar of the movement, by a pin in the lower pillar, and by a screw into the lower dial-foot. In addition the L-shaped pieces of the bottom are screwed to the dial.
The top has two riveted ledges to form fitments for the doors. The top is separately attached to the movement by a screw in the upper dial-foot.
The doors are hinged between top and bottom; they can be removed by unscrewing the top. The lower-left hinge has been repaired. Both doors are made of thinner material than the case and the workmanship is less solid; they are replacements.
The case carries traces of black paint.
The dial is an engraved brass plate, gilded on the outside only. It has been extended at the top by riveting additional material to it. The plate is pierced and engraved with volutes and architectural motifs. The added material at the top consists of a ledge with volutes and a figure of the sun; the engraving of the latter is very similar to that of the moons on the lunar disc, which suggests that these additions date from the time of manufacture.
The upper portion of the dial has a large aperture, originally covered with glass or crystal, through which the cross-beat can be viewed (glass now missing, the bezzel secured by four screws). Under this are three dials and the aperture for the moon.
The main dial has a silver chapeterring riveted to the plate by the twelve touch-knobs. The ring is marked I - XII with half-hour marks and a quarter scale, for the twelve hours, read by a steel hand. Within the chapterring the plate is engraved with the signs of the zodiac, which is centred by an aperture covered by a riveted silver disc. This disc is divided in four sections, marked with the names of the seasons in German ("FRILING - SVMER - HERBST - WINTER"), and with two series of numbers 8 - 16. The zodiac ring and the silver disc form the annual calendar, read by a steel hand having a gilded figure of the sun at the tip and shaped like the moon at the tail. The figures indicate the approximate length of the day and the night at the time of the year; the scales go from longer than 7 hours to less than 17 hours, which is appropriate for Arnstadt (Latitude ca.51, longest day ca.16½ hours).
The lunar dial, which revolves behind the aperture for the moon, consists of a blued steel disc, to which are riveted a gilded brass ring and two gilded brass figures of the moon. The ring has a scale of twice 29+ and is numbered twice 1 - 25, for the lunar month.
The two subsidiary dials each consist of a gilded brass disc and a silver ring riveted to the plate. On the left the disc is engraved with the names of the planets and the ring with their symbols; the dial is read by a steel hand and shows the day of the week. On the left the disc lists the months with their lengths, and the ring is divided 1 - 31 with every odd date marked; this dial is also read by a steel hand and indicates the date.
Flat frame movement, the frame constructed of steel. At top and bottom the front bar is extended at right angles to form the dial-feet; on the other side two L-shaped "pillars" have been welded to the bar.
The train wheels all run in brass bushes; the scape wheel runs in two brass arms that have been dove-tailed into the steel bars. the train-wheels have three crossings except for the great wheel which is solid. The wheels of the under-dial work are mostly of steel; they are solid and do not have bushed holes.
1 rev. in ← ║ 90 72
2 hours ║ ── ── 26 (x 2)
║ 6 6
Great wheel: the wheel carries the steel click and click-spring. Cordwheel integral with the ratchet wheel of 22; the assembly is riveted with three brass rivets.
Escapement: cross-beat with two geared balances, each verge having one pallet. The top balance is the outward one. The escapement is mounted as a separate unit, carried by a blued-steel disc which is pinned to the front bar of the movement by three feet (the two feet at the bottom repositioned to allow room for the under-dial work). The brass potence is screwed to the disc; a small brass cock, pinned to the potence over a stud, carries an ornamental gilded brass star (originally pinned, now riveted).
The arms of the balances are of steel, with engraved silver cherubs riveted to them for weights; they are geared by brass half-wheels of 6 teeth each. The backs of the cherubs carry traces of wax and lacquer as well as a small piece of metal, for poising.
Most of the wheels of the under-dial work are carried by the front bar, which has two extensions sideways; these extensions have brass blocks riveted to them, to take the wheels for the day and the date.
1 1 60 ┐
─ ───── ── │
day ← 7 8 ┌ 8 15 │
│ │ 10 ║ ← 1 rev. in 2 hours
1 ┘ │ ── ║
── ├ 60 ║
date ← 31 │ ↓
1 1 16 ┤
── ─ ── │
calendar ← 52 7 32 │
4 6 ┘
moon ← 63 45
The drive for the under-dial work is a brass pinion of 10, mounted lossely on a square on the great-wheel arbor. This pinion meshes with a steel wheel of 60, which is friction-tight on its arbor. Outside the frame this arbor carries a sandwich of a steel wheel (60) riveted to a brass wheel (16). This assembly is pinned to a square on the arbor, which additionally carries a brass pinion (6) which is friction-tight on the square; the wheel of 60 meshes with a brass wheel of 15. All other wheels are of steel; however, all five endless screws and the wheels they mesh with are of brass, except the calendar wheel (52) which is of steel. The wheels for calendar (52), date (31) and day (7) as well as the wheel for the moon (63) are friction-tight on their arbors. The pinion of 4 is a lantern of four riveted pins.
The wheels for the moon are carried by an arm screwed to the front bar; the first wheel (45) is retained by shaped arm similarly attached. The arbor of the lunar disc (wheel of 63) has a square projecting throught the dial, for setting.
The clock has not been converted: the few alterations in the construction appear to be due to changes in the basic design.
Great wheel: 1 rev. in 2 hours.
Escapement: 4680 beats per hour.
Day - 1 rev. in 7 days.
Date - 1 rev. in 31 days.
Calendar - 1 rev. in 364 days.
Moon - 1 rev. in 29.5313 days.
Clock: height - 313 mm
width - 164 mm
depth (without hands and arbors) - 77 mm
Movement: distance between the bars - 28 mm
distance between the pillars - 176 mm
HISTORY AND PROVENANCE.
Octavius Morgan collection; it is not known when or where Morgan acquired the clock.
Octavius Morgan bequest, 1888; reg.1888,12-1,142.
In 1988 Richard Good published a technical description, which includes many measurements.
The signature of the clock is puzzling: it consists solely of the place-name "Arn stad" and there appears to be no space for a makers name (unless it was painted on the glass cover of the escapement, which is now lost). However, research by the late Dr.W.P.Buchler, Brunswick, shows that for many years the only clockmaker in Arnstadt was Wolfgang I Hager. He was born 1603 in Steiermark as son of the clockmaker Melchior I Hager (1575-1636), but was expelled as a protestant, as was his elder brother the clockmaker Melchior II Hager (ca.1602-1658). Melchior went to Frankfurt a.M., but Wolfgang was in 1627 invited by Count Christian Günther I von Schwarzburg-Sonderhausen (1578-1642) to come to his residence Sondershausen near Arnstadt. Wolfgang was made court-clockmaker and court-mechanic; he died in 1674. He had two sons who succeeded him in the trade and there were clockmakers Hager until the end of the 18th century 1).
For the cross-beat escapement, invented in ca.1570 by Jost Bürgi of Kassel (later Prague), see 1973,2-2,1. It may be noted that Hager understood that with this escapement he could use a scape wheel with an even number of teeth; it makes 1 rev. in 40 seconds.
The lunar train is exceptionally accurate; it incorporates a wheelcount based on a lunation of 29 days + 45 minutes, or 945 periods of 45 minutes. The reduction to periods of 45 minutes occurs at the wheel of 60, which makes 1 rev. in 12 hours or 16 x 45 mins. The wheel of 45 makes 1 rev. in 120 x 45 mins., and the wheel of 63 1 rev. in 1890 x 45 mins. (= 2 lunations). As far as is known at present this very unusual train-count was first used by Jobst Bürgi 2), the same maker who invented the cross-beat escapement. The presence of both innovations in the present clock suggests either that Hager somehow had contact with Bürgi (who died in 1632), or that Hager was able to study one or more of Bürgi's clocks, perhaps before arriving in Arnstadt.
Compared to many wall clocks of this general type the present clock is exceptionally well made. The steelwork is of particularly high quality; the brass, curiously, has many casting-flaws.
1) Letter from Dr.W.P.Buchler of 23rd Dec.1992; Abeler (1976) 247-8, which is also based on information supplied by Dr.Buchler.
2) This lunar train is present in Bürgi's crystal clock of 1622/3: Kunsthistorisches Museum, Vienna (Leopold  208, 210).
Is Arnstadt near Lemgo? It is not.
Check when Buchler died.
Yellow brazing on the arms that carry the endless screws.
The maker was clearly more at home with steel than with brass: the steelwork is lovely, the brass is full of holes.
BIBLIOGRAPHY (Pauline Wholey – 2019)
Lloyd (1964) H.A.Lloyd, The Collector's Dictionary of Clocks (London 1964).
Maurice (1976) K.Maurice, Die deutsche Räderuhr, 2 vols. (Munich 1976). Page numbers refer to vol.1, fig. numbers to vol.2.
Edwardes (1977) E.L.Edwardes, The Story of the Pemdulum Clock (Altrincham 1977).
Tait (1983) H.Tait, Clocks and Watches (London 1983).
Good (1988) R.Good, `My favourite clock, a weight driven wall clock', Clocks Vol.10 no.11 (May 1988) 1, 9 11.
Tölke (1994) - H.F.Tölke, `Ein Wurm in der Uhr!' I, AU 6/94 (October/November 1994) 12-28.
Oestmann (1999) - G.Oestmann, Uhren und wissenschaftliche Instrumente der Familie Hager (Braunschweig 1999).
Hans-F. von Tölke, Ein Wurm in der Uhr, Uhren 1994, no.5, pp12-28 [21-22].
- On display (G38/dc4)
- Exhibition history
1999 10 Dec-2010 5 Mar, Germany, Wolfenbüttel, Herzog August Library, Fugit hora sicut umbra: Wie der Schatten flieht die Stunde. Uhren und Instrumente der Famile Hager aus Braunschweig - Wolfenbüttel und Arnstadt
- Acquisition date
- Britain, Europe and Prehistory
- Registration number