1

MEMO OOSTERWIJCK D9: "A Royal 'Haagseklok'" Appendix 3, Open-Research.

Reviewed by Keith Piggott

D9 Clock with striking; cartouche signed 'Severijn Oosterwijck Fecit Haghe Met privilege'. Special features: bell inside the case; dial plate turning on pins. Reference 2, 34 -35 (private collection).

Excerpt from Dr.Reinier Plomp, "The earliest Dutch and French pendulum clocks, 1657-1662",

given 'D9' [N9], (Op.Cit. 'Chronology', Kunstpedia, 2008). For other Oosterwijck pendulum clocks;

see Dr.R.Plomp,"Spring-driven Dutch pendulum clocks 1657-1700", (Op.Cit., 'Pendulums', pp.178-

179, #84; pp.180-181, #85); "Lieberge alarum-timepiece", (Sotheby's Amsterdam 21/02/1995, lot 324);

also H.M.Vehmeyer, (Op.Cit., LC16~D13, LC17 attributed). Dr Plomp's 'D' numbers used throughout.

This early Severijn Oosterwijck 'Haagseklok' with

hour strike, in a simple ebony veneered box-case,

owned by the 'Boom-Time Foundation' who have

kindly given consent to publish, was exhibited at

‘Museum van het Nederlandse Uurwerk' (MNU)

Zaandam (2010), also "Huygens' Legacy" (exhibit

11, Paleis Het Loo, Apeldoorn, 2004). All images,

wheel train data and the general dimensions, are

provided by courtesy of Dutch horologist-restorer

Melgert Spaander of Zutphen, copyright holder of

all images unless excepted, who says movement

is "99% original". I acknowledge Carel Hofland,

director of the MNU, who obtained for me the

necessary consents by the BoomTime Foundation.

'Huygens' Legacy' excited our interest in this

previously unpublished Oosterwijck Haagseklok,

though Berry van Lieshout and I had reservations

about evidence of 'improvers'. I expected Melgert

Spaander's report to reveal a movement that

should dovetail neatly into the 'Chronology' of

Hague striking clocks, to support their straight-

forward evolution. In fact Melgert's report threw

up some challenging questions, about Severijn

Oosterwijck's work practices and the inter-change

of even earlier features, also common to Coster

timepieces, also one totally unexpected omission, Severijn Oosterwijck 'Clock with Striking' (D9)

all questions I shall address in appropriate contexts. Courtesy of the BoomTime Foundation.

Copyright Melgert Spaander, Zutphen.

Severyn Oosterwyck's repoussé cartouche having

Dolphin supporters of silvered copper is of a lesser

quality than Claude Pascal's example, D14, both

variants of Pascal's earlier* engraved pattern, D13

(HMV LC12) also used by J.Bernard van Stryp of

Anvers, (see MemoStryp). Oosterwijck's signature

now includes 'Fecit' like his 1662 Longitude Timer

(signed on back-plate), yet this repoussé cartouche

still bears Huygens' early legend "Met privilege";

exactly as his purportedly later movement signed

on similar but finely engraved Dolphin cartouche

(see MHV LC16). One might expect to see the

Dolphin cartouche reproduced as a casting; I recall

"Severyn Oosterwijck Fecit Haghe Met privilege" none. [*nb. 1st engraved, 2nd repoussé, 3rd cast].

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The subject Oosterwijck D9 adds a great

deal to our limited knowledge of his early

pendulum clocks having hour strike,

exemplifed by the later discovery of his

Royal Haagseklok (RH): see Part I.

Readers may access Melgert's Spaander's

'radschema' (wheel train layouts), also his

'specificatie' (specification). Melgert's data

is uploaded into the open research matrix;

here as an edited Appendix One, Table 5,

Coster D8. This table compares, probably,

the three earliest extant Hague clocks to

have strike; ie. Oosterwijck's RH and D9,

also Salomon Coster's D8. I contend that

only analysis of wheel trains, dimensions

and witness-marks shall reveal the Hague-

clocks' evolution and chronology, to credit

each maker's contribution. With sufficient

data we may refine this model, a matrix's

value is not immediate but is dependent

upon new and thorough open research.

Generally, movements exude similarities,

but nothing conclusively. However, their

significant dissimilarities reveal far more;

1. layout of centre arbor, wheel, pinion;

2. strike train having 10 or 12 pins/leafs;

3. presence or absence of stop-work;

4. having English or Dutch potences;

5. going trains having 4 or 3 spokes.

1. Coster timepieces set original standard;

his centre-wheels set against back-plates

fixed to centre-pinions, the narrow centre

arbors having intergral collets at the front-

plates. Two of these early strikers concur;

ie. Coster D8, Oosterwijck D9. Whereas

Oosterwijck RH separates its centre-wheel

towards the front-plate on very substantial

and over-engineered tapered centre-arbor.

2. So far, only Oosterwijck's RH and D9

use a count-wheel pinion having 10 leafs

and a pinwheel having 10 pins. Whereas

Costers' D8, D10, have 12 leafs, 12 pins,

becoming the ubiquitous newer standard.

3. Dutch split-barrels, driving both going

and strike trains, are remarkable for their

variety, no standard dominated for several years to come. Some set 'ratchets' on the barrel, on backplate,

then frontplate again, cf. timepieces D1-D4. 'Stop-work' might be hidden under ratchet (RH), or set alone

at the opposite end of barrel as ratchet, (D8). Remarkably, Oosterwijck D9 appears never to have had any

stop-work, being in this respect like Coster timepiece D4. It is the exception to the rule; also at odds to

my hypothesis of association with split-barrel as the Coster-Fromanteel contract 'secreet'. Was the "stop",

then, merely an optional extra, only supplied at additional cost? That does not seem likely.

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Yet the French did adopt the 'split-barrel' without its associated 'stop-work', and D9 does appear to have

been 'improved', apparently in France. So might D9's 'stop-less' split-barrel be; a). a Dutch pre-Contract

model - thus pre-secreet? b). a cheaper domestic version of RH? c). an export model intended for

France, being sold without the 'secreet'? d). a replaced barrel cap? e). a French barrel? D9's lack of stop-

work, indeed, is a conundrum. Are other Dutch split-barrels known where stop-work was omitted?

Dissimilarities 4-5 are limited to Oosterwijck's RH, unique in having English potences, also in having a

4-spoke going-train, (see Part I). His clock D9 adopts both Coster's block potence and 3-spoke standards.

But matrices and probability graphs never reveal the complete story - which Severyn Oosterwijck's clock

D9 fully deserves. Oosterwijck's D9 possesses several similar features as RH, but all are slightly larger

and/or more ornate in significant details; therefore, by most horological tenets D9 is the later clock. Yet

notwithstanding that premise, D9 curiously shares a few early features with Coster timepieces, especially

D4. That was not anticipated, so where a view must be taken I shall disclose known conflicts of evidence.

Already I mentioned reservations at the evidence of improvers' handiwork - which always muddies the

horology. One improvement is the garish chemical blueing to steel components, others are less obvious.

Assuming readers' familiarity with "A Royal Haagseklok" Part 1, also with "MemoCosterD8", I shall

present my observations in note form - enhancing points of similarity and dissimilarity between the three.

CASE: H. 269 W 212 D 103mm [cf. RH H 254 W 165 D 92.5 cf. D8 H 276 W ? D ?]

Box case having no side windows, (Plomp's 1st Characteristic); the door opened by the winder key on

right side, p.1. (Plomp's 6th Characteristic); cf. RH and D8. The dense Ebony veeeer applied to a fruit

wood carcase; the interior being veneered in plain reddish Padouk without internal parquetry.

Unlike RH Door (Plomp's 2nd Characteristic), D9 has proud mouldings deeper than D8.

The early Box-Cases of RH, D8 and D9, are all recognisably by the same Casemaker.

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Door Hinges are set into rebates over ebony

veneers, being indistinguishable from RH.

Dust sills around door - like RH and D8.

All facing veneer corner angles are mitred.

The box/door veneers are 'windmill' lapped.

Recognisably the same casemaker as RH, D8.

Early Box Case with single inferior sound-hole

adjcent to a dial-mounted bell, like RH and D8

but which have two sound-holes; Chronology

may depend on whether one hole was found to

be inadequate (D9 ante), or whether two holes

were found to be surplus to needs (D9 post).

Later Oosterwijck strikers, #84 #85, have one.

The Eye Hangers are brass, circular,

set on short outspread capstans. [A

suitable model for RH replacements]

Left: Beautifully crennelated bell-nut

represents the subtle trend towards the Above: D9 pivot-plate is screwed to the dial like RH, D8's dial

increased decoration of simple RH-D8 is hinged. D9 has a single sound-hole, RH and D8, have two.

designs, to eventual over-elaboration of Box sides chopped for pendulum-arc, (RH was chopped later,

Hague clocks - aping Paris counterparts. but D8 has a higher square cut-out for the associated alarum.

Melgert Spaander noted "Bg519" inscribed beneath the box.

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DIAL-PLATE: 232 mm by 172 mm [cf. RH 212 mm by 165 mm, cf. D8 228 mm by 171 mm]

Hammered brass dial, but apparently using a different tool to RH, and, untypically, is part blackened.

Similar dial cut-out to recess the Reverse Minute-Cock - like RH, but off-centre in a lower position.

Dial swivels on pins mounted on upper and lower plates screwed to the dialplate, exactly like RH.

RH form of dial-mounted, tapering 'obelisk', Bell-Stand - now recognisably Oosterwijck's style, but

has no Holdfast - therefore D9 like D8 was not intended for travelling, ie. unlike Charles II's RH.

Round dial-feet are heavier than RH, a lower

stud is narrower due to constraints of space,

by resited lower minute cock position. The dial-latch is formed exactly like the RH latch but not so well

finished at the leaf foot. The pendulum access hole is rectangular, like RH, although larger. To its left is

scratched "AHO 31/1/87" also "8/10/87". Might "AHO" and "Bg519" offer clues to its provenance?

CARTOUCHE (signature shield): At this early date the silvered copper signature

plate, untypically, is repoussé rather than flat

Untypically too, at this date, signature includes

"Fecit" (made); untypically too on a repoussé

shield is Huygens' first 'Met privilege' legend.

I infer above that designs are firstly engraved,

then appear in repoussé, then as castings. The

first examples of Hague signature plates are

flat, ie. Coster, Oosterwijck, Pascal, Hanet,

Visbagh, all typically shaped as lambrequins,

with simple engraved designs. Dolphin pattern

first appears as an engraved plate, by Claude

Pascal, who may have made first in repoussé.

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CHAPTER RING:

Silvered brass ring having four brass dial-studs set symetrically and pinned at obverse, (Plomp's 7th

Characteristic), The diameter (142 mm) is virtually identical to RH (143mm), but a wider annulus

than RH. This neat design sets the standard for Hague Clocks, ie. ordinal Roman hours, half-hours

marked by cruciform flower-head on stalk, quarter-hours marked between inner-lines, every minute

numbered between outer lines, single minutes 1-9 not scored through, [Patterns PCR 6th State].

After Oosterwijck RH, (PCR 4th State), his next clocks all appear to follow this classic new D9 design,

PCR 6th State. It is almost an Oosterwijck 'trade mark', [cf. D18 chapter-ring over Pieter Visbach].

HANDS: D9 engraved and

silvered brass, untypically

looped; unlike Coster D1,

D2, D4, D5 and RH (lobed).

Part I cites the looped hand

found on the timepiece, now

designated Coster D3. I have

suggested Oosterwijck might

be recalling an earlier Coster

form, before his lobed hand.

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FRONT-PLATE: 117.6 mm by 95.4 mm [cf. RH 115mm by 94 mm; D8 120 mm by 98 mm]

Four Cannon Pillars, riveted at

front-plate, pinned at back-plate.

This is an earlier appearance of

cylindrical Cannon Pillar (PP6);

seen in his 'Longitude Timer' of

1662, see Appendix Five; also

in his #84 (HMV LC16); also

typically used by Johannes van

Ceulen Sr. from the late 1680s.

Oosterwijck's #85 (HMV LC17)

adopts the English variation of

cannon having a central knop.

D9 plate separation 39 mm

RH plate separation 38 mm

D8 plate separation mm

D9 plate thickness 1.8-2.7 mm

RH plate thickness av. 2.2 mm

D8 plate thickness mm

Barring minor variations in their

springs and cock position, plants

of wheel-trains and main strike

components closely follows RH

and D8, also D10 etc.

MOTION-WORK AND BRIDGE:

Unlike the typical squared bridges of RH and D8, (set on pins and

screwed to the front-plate), the subject D9, like Oosterwijck's #84,

reverts to the smaller round-footed bridge having a circular plate in

the manner of Coster timepieces D1, D2, D4, D5. But Oosterwijck

D9 bridge is entirely brass; without the steel plate shared by Coster's

timepieces and also his subsequent striker Plomp #84 (HMV LC16).

Oosterwijck's "Longitude Timer" shares a similar, but more angular,

all brass bridge.

The Reverse-Minute Wheel (30 teeth, 21.5 mm diameter) and its

Cock are relocated downwards to VII, (from XII in RH and D8).

The Cock has a cut-away foot to clear the rising hammer, which is

all steel and slim enough not to need cut-away plate edge, (cf. RH).

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FRONT-PLATE: D9 has plain rectangular plate,

not cut-away at hammer-side, (cf. RH), nor is its

lower corner reduced - to clear the dial mounted

bell, (cf. Coster D8, D10, Oosterwijck #84, etc.).

The upper front-plate is free from obstructions.

Note the winding square has hardly any taper, a

typical feature of Hague clocks. But unlike RH,

the front-plate exposes the extended collar of its

steel Ratchet-wheel, so the pin through the barrel

arbor is visible, proud of the front-plate, cf. D8.

This feature is common to Coster D8, D10, and

subsequent Oosterwijck clocks.

Often it is difficult to reconcile first appearances

of any new feature, like the visible ratchet collar

or the count-wheel pointer, especially whenever

found untypically in an early phase of movement.

For that reason, Dr. Plomp's D9 'Chronology' is

perceptive as in the subject clock, the front-plate

and back-plate look like very different periods, or

even two different clocks! At least it shows where

Oosterwijck had directed most of his attention; or

where later improvers saw the most potential.

Comparing frontplate of D9, with RH and D8 below, shows their highly significant similarities in

movement layouts and in plates, (ébauches). Admittedly, the several obviuos differences in added

details might well help to distinguish the finishing hands involved in these Hague workshops.

Elevations of early Hague strikers can be compared at Supplementary Views, Comparables, Front-Plates.

Comparison of clock dimensions and wheel trains is best facilitated via the Open-Research Matrix.

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BACK-PLATE: 117.6 mm by 95.4 mm [cf. RH 115mm by 94 mm; D8 120 mm by 98 mm]

Oosterwijck's Lieberge alarum timepiece is the first to have a signed back-plate; but earlier movements

are not signed, but like Lieberge this back-plate has scored lines - triple and single; authors of "Huygens'

Legacy" suggest is characteristic of Oosterwijck; [although the backplate of Coster alarum timepiece 'D5'

also has scribed lines, with ratchet on backplate in later manner]. But D9 also has a pronounced chamfer

to the edge of the plate; not previously seen - and rarely later. And D9 also sports, probably, the earliest

Dutch numbered and ringed count-wheel with a blued hand to indicate the hour being struck.- only useful

in resetting should the hands become out-of-synch with the locking plate. Unlike RH and D8, the early

key-plate securing early count-wheels is replaced by an untypical steel hand fitted to the stud by a robust

pinned tenon; ditto Oosterwijck's #84, #85 (see 'Pendulums') and HMV LC17 attributed; two having

plain unscored plates, none having a chamfer, the two latter also having 5-wheel trains, and #85 having a

backplate ratchet. Mixed signals! One must always be circumspect, against 'improvement' for commercial

advantage, or misguided conservation, although maker's too varied each individual clock to order.

Dimensions, of both the plates and the

pillars, accords to Oosterwijck's model

RH; (ditto Coster D8, etc.).

The pin to an upper pillar is oddly set

across and over the foot of the triangular

back-cock. Clock makers typically set

pins symmetrically but other irregular

examples abound.

Detent-spring of thin steel wire is

untypical - Berry reports evidence of a

filled steady hole, probably for an

original typical blade spring?

Oil sinks to the pivots are later

refinements, typical of 18th/19th

century French repairers. Might it be a

clue as to why there is no stop-work to

split-barrel?

Locking Detent 'under' Count-wheel -

but a scored witness mark suggests it

once was 'above' detent - facing

inwards, against the plate.

All wheel train pivot-holes have

previously been rebushed, some twice

Early movement - untypical highly decorated back-plate. over and not well executed.

Rebushings

and

Oil-sinks.

nb. pre-conservation!

Scoring under Detent

(possibly reversed, or

originally set edge-on

like RH and D8).

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SPLIT-BARREL:

Dimensions: D9 RH D8 (mm)

Length 31.3 25.0

Diameter 42.9 43.0

Going G1 49.1 49.4

Teeth 72 72 72

Strike S1 49.0 49.5

Teeth 80 80 72

D9's longer barrel allows for a wider

mainspring; more powerful than RH.

Going wheel G1 fixed at the Rear.

Mainspring (W 25mm) replaced.

Strike wheel S1 at Front runs free.

S1 teeth are all similarly distorted.

S1 bears the barrel ratchet, flat click

-spring, and replaced modern click.

Visible here is the plain Centre-arbor;

the pinion and wheel at back-plate;

Coster's integral collet at front-plate.

Barrel Arbor has stepped squares at

the front, the first being to wind, the

second square is pinned at the collar

of the ratchet - like Coster D8, D10 -

but unlike Oosterwijck's RH which

has a curious subsidiary cam set over

its collarless ratchet-wheel.

SPLIT-BARREL opened for conservation.

Original Barrel-Arbor resting on the front Cap

and replacement spring. Note stepped squares,

pin-hole, and stubby spring-hook. No evidence BARREL CASING WITH FIXED GOING-WHEEL

for a rear-leaf or a rear-pin for 'stop-work'. Note damaged barrel-hook, repaired by Mr Spaander.

STOP-WORK: the powerful old spring broke when over-wound for an exhibition, damaging both spring

and barrel-casing hook. That accident perfectly illustrates original raison d'être for having stop-work! Its

presence, first seen in RH, would have prevented catastrophe; a new safety feature, foreseen, but omitted?

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RATCHET-WORK: The flat brass Click-Spring encircling low relief

steel Ratchet Wheel, 25 teeth, Ø 30.2 mm; (RH 21 teeth Ø 34.4 mm);

permits a longer barrel 31.3 mm (RH 25.0 mm) for wider mainspring,

ie. more power. The steel click is a replacement. Clearly visible is the

ground wheel, S1, showing uniform tooth deformations that Melgert has

ascribed to having too strong a mainspring, (anyway broken, replaced).

STOP-WORK: No evidence for Stop-Work on the Barrel-Cap or the Barrel-Arbor! cf. Coster D4.

Thinking laterally, I even looked for the unlikely use of a stop mounted on the front-plate, driven by

an extended pin from the barrel arbor - of course there is no evidence. Yet, on a Dutch split-barrel,

the absence of Stop-work surely demand explanation, especially seeing my hypothesis of Split-Barrel

with Stopwork as being the 1657 Contractual secreet. Might a French hand explain?

Oosterwijck D9

now has French

style oil-sinks, so

might the barrel

itself be altered,

or even changed,

while in France?

French makers

omit stop-work.

Examination of

Pascal or Hanet

clocks changing

from the Dutch

model into the

French model

might provide

valuable clues.

<nb. Detached

Centre-wheel.

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GOING TRAIN:

Oosterwijck's four-wheel going train, the Centre, Contrate and Escape wheels all having 3- Spokes, being

typical for Hague clocks, (see previous page); whereas Oosterwijck's RH has the extremely rare 4-spoke

going train. D9 Centre-Wheel has a brass collet at rear face - a shallow cone rather than typical dome.

Oosterwijck's new narrow, and untapering, Centre Arbor has Coster's integral steel collet set at the front-

plate, (cf. Coster D1-D5, D8). The Contrate Wheel is broad, untapered, and has only a single ring running

along the base of the teeth. These images do not show the detail of whether punched or scribed marking

for hand cutting, which this should have been. Coster's Dutch style Potences are each screwed internally.

HUYGENS' CRUTCHED VERGE and

HIS PENDULUM SUSPENSION.

Short Verge in Coster-type Potence-block

with integral front-pivot, (RH has a strap-

potence). The rear pivot set in a cock on a

triangular foot, on IX side, (opposite RH).

Centre-Wheel (in a distressed state) before

conservation, fixed to Pinion at backplate,

cf. Coster timepieces D1-D5 also strikers

D8, D10; all being unlike RH (below).

Centre Layout of Oosterwijck's RH. Huygens' Cheeks: probably altered; Cycloids would be

incorrect for 1660 date, Huygens was still experimenting.

Silk suspension here is too short to work; Huygens intended the silk (not the rod) to wrap itself to

and along the cheeks to create its evolute. Blued steel screw across cheeks has late form. Modern?

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MOTION WORK:

Bridge is a circular plate on rounded feet, one piece wrought brass but resembles Coster D1-D2-D4-D5,

Minute wheel cock is moved to inferior position, cut-away for hammer; it recesses into dialplate, cf. RH.

Hour-Wheel 72 teeth (Ø 37.4 mm), Reverse and Minute Wheels 30 teeth (Ø 21.8 mm), Pinion 6 (ø 4.2).

STRIKE WORK:

The lifting piece, drop-hammer, and general layout of strike train all follows Oosterwijck's RH. In one

respect only, Oosterwijck's D9 and RH share Pinwheel and Count-wheel Pinion numbers of 10 and 10.

Whereas Coster D8 also D10, (and I suspect all subsequent Chronology), share 12 pins and 12 leafs.

One-piece steel, round-head, gravity-drop hammer; assisted by brass wire spring (of uncertain age).

Whereas there is no 'standard' for early hammers, this does appear to have an uncharacteristic modernity.

Notches beneath the nose of the stop (below) suggest the hammer tail was longer, progressively reduced?

Or this hammer is a replacement? Note cross-filed groove; Decoration? or made for another pin angle?

Carved brass blade Stop-Spring: (resembles contemporary steel lock-springs by Bescian gunsmiths)

Among Hague striking clocks, there is only one remotely similar, that being Oosterwijck's own RH, and

that only in its vertical foot to the reversed "L" shape brass stop-spring - also set into the plate by studs.

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COUNT-WHEEL (LOCKING-PLATE):

The profiled, multiple ringed Locking-Plate is numbered 1-12 (arabic). Wide slots suggest single 1/2 hour

blow? The plate is not held by a 'key-plate'(like RH, D8, D10, D18, etc). Untypically for any first period

Hague striker, the wheel is pinned fast to its mounting stud in what, commonly, is regarded as the French

way. Certainly it appears in Paris circa 1665, with Thuret. Dr.Plomp records similar count-wheel pointers

by Baronneau, Du Hamel, Hanet, Martinot, all circa 1665 (Reinier Plomp, 'Pendules' Chapt.2, pp.44-49).

Such pointers, indicating the hour being struck, are superfluous in use, and only useful when resetting the

strike should the dial hands become out-of-synch after daily re-setting against the regulating Sundial.

Oosterwijck's slender pointer is fixed to the stud by 'I' bar tenon; his other examples are more robust, also

geometrically faceted, (cf. #84 HMV LC16, #85, HMV LC17; also Nicolaes Hanet, F12). At Part I,

I explore Severijn Oosterwijck's inventiveness at some length; now, it would appear that, we also should

credit him with this, henceforth, Dutch novelty. However, one cannot yet rule out the possibility of Pascal

or Hanet, while still in the Hague, each having closer involvements with Oosterwijck than was realised

hitherto. Were it not for the discovery of a Notary's rough draft contract, who ever would have known of,

or dared to assert, John Fromanteel's involvement with Salomon Coster's pendulum oeuvre in 1657?

15

STRIKE-DETENT GATES:

Developed leaf forms, each arbor having decorative profiles; unlike RH arbors. (cf. D8, D10, D18).

D9 Carved steel Gates (obverse)

Gates and Pointer (reverse)

Cf. Gates/Arbors of RH, D8, D18?

16

FLY: Heavy fabricated fly, basically a Lozenge casting then profiled into 'ogee' paddles, cf. RH, D8, D10.

Oosterwijck D9 Fly has a leaf-spring set across fly-arbor, his RH has a bow-spring at one end.

"Coster" D8 - Strike Side with simple Gates.

Compare the increased elaborations to Gate and Arbors Nb. Fromanteel's pivoted-pendulum, as found,

of Oosterwijck's D9 with Salomon Coster's D8 (right). clearly retrograde conversion from Huygens'

way. (Courtesy of MNU Zaandam).

17

BELL:

The polished high-domed early bell, having flat pad above, the square NUT crenellated (notched), being

mounted dome facing on an obelisk dial bell-stand - like all the first series Hague striking clocks. Later,

the bell was reversed dome-to-dial (Pascal), the bell next moved to a superior position above the case.

Mystery Oosterwijck Haagseklok - Dial like his #84

(HMV LC16), but in a case like Claude Pascal's (see Dr.

R.Plomp 'Pendulums' #91). The author welcomes any

information about this clock, its present whereabouts,

and its availability for examination for open research.

In all these respects, and because of the evident cross-over of several very early features among his

contemporaries' movements, also seeing the several apparently anachronistic later features, Oosterwijck's

subject clock 'D9' presses home the need for "open research".

At PART I, from a number of construction details in common, and evidence for their evolution, I made

out the case for the Royal Haagseklok by Severijn Oosterwijck being the model and "prototype" for both

the Striking clocks bearing Salomon Coster's name, if not in fact made by Oosterwijck himself. I also

assert that Oosterwijck's Royal Haasgseklok is also the model (at least) for the earliest striking clocks

bearing the signatures of Pieter Visbagh (Visbach) and Claude Pascal.

Ideally, Severijn Oosterwijck's earliest movements should all be directly compared by a suitably qualified

conservator; in particular his Royal Haagseklok; the subject clock given 'D9' in Dutch Chronology; his

movement shown in Dr.Plomp's 'Pendulums' #84 (MHV, LC16); his 'Lieberge alarum timepiece'; and

the attributed movement with five-wheel train and a back-ratchet, 'D21' (MHV LC17). I should include

early Hague movements by Claude Pascal, Pieter Visbagh, even Coster trained Christiaan Reijnaert too.

Oosterwijck’s dateable sea-clock (1662), at Appendix Five, adds further evidence of their evolution.

Copyright text, Keith Piggott 15th March 2011 Copyright images, Melgert Spaander

Acknowledging assistance by the Museum voor het Nederlandse Uurwerk, Zaandam, (MNU).

Published by kind permission of the "BoomTime Foundation"

▲ (Back to Top) HF ▲ (Back to RH)

There follows two 'aide memoires' giving dimensions of RH and D8 movements, also images of D8.

18

AIDE MEMOIRE - COMPARABLE OOSTERWIJCK STRIKING CLOCK

ROYAL HAAGSEKLOK, Appendix One, Tables 2-3

Five matrices can be accessed via Appendix One;

For more complete data on other early European

pendulum clocks go to openresearch.xls.

Images relating to Comparables, References, and

component Patterns may all be downloaded at

Supplementary Views. If you you wish to share

your early pendulum data for 'open research',

go to submitdata.xls.

19

ROYAL HAAGSEKLOK, Appendix Three, Memoranda: Salomon Coster 'D8' (Courtesy of MNU)

GOING TRAIN:

Count 65/5x60/5x58/60 = 150.8 beats

Nominal Pendulum 15.8 cms

G4 Escape wheel (schaekelrad/gangrad) p.5 / 29 teeth

G3 Contrate-wheel (kroonrad) p.5 / 60 teeth

G2 Centre-wheel (centrumrad) p.6 / 65 teeth

G1 First-wheel (grondrad) fixed to pinion 72 teeth

nb. First and Contrate common with RH, D9.

G2 Arbor tapers, shallow front relief for S1, front collet.

G2 Centre wheel at back-plate fixed behind 6 leaf Pinion.

like Coster timepieces; also D8, D9, D10; unlike RH!

MOTION WORK: Identical to Oosterwijck RH, but having

significant exceptions; ie. Pinion of 12 on S2 Arbor, Pinwheel

of 12 pins; as new and henceforth ubiquitous strike standard.

SPLIT-BARREL: Yes

Ratchet: on front barrel cap. Stop-Work: to be examined.

STRIKE TRAIN: S5 Fly (windvleugel) Dr.Grimbergen p.5? p.6 / 2 vane

Fly unreduced, open centre, cf. RH D9 D10

S4 Fourth (slagrad) p.6 / 42 teeth

S3 Warning (voorslagrad) dome-collet 2 pins p.5 / 48 teeth

S2 Pin (pennenrad) 12 strike Pins p.8 / 60 teeth

nb. Count-Wheel Pinion of 12 leaves

S1 First (veertonrad/grondrad) 72 teeth

nb. planted at front of split-barrel.

Strike Gates: 3 steel scrolls, 2 short, simple 'C' form.

Count-wheel 12 unequal slots I to XII.

Drive-wheel 78 teeth, Pinion of 12, Pin-Wheel 12 pins

Strike Work:

Layout and form identical to Oosterwijck's Royal Hagseklok,

but Coster's having 12 pins and pinion of 12; new standard.

Whereas uniquely Oosterwijck RH and D9 have just 10 pins,

with count-wheel pinions of 10 leafs; (inferring their earlier

chronology in the evolution of Hague clock strike-work).

Comparing Going-Trains: (green shows commonality) Comparing Strike-Trains:

Coster escapes D3 5/27 D8 5/29

Oosterwijck escapes RH 5/27 D9 5/27 RH 80-8/60-6/48-6/48-5/Fly

Coster contrates D3 5/64, D8 5/60 D9 80-8/60-6/60-6/60-6/Fly

Oosterwijck contrates RH 5/60 D9 5/60 Coster D8 72-8/60-5/48-6/42-6/Fly

Summary: Oosterwijck RH Strike train having 10 Strike-Pins to 10 leaf Pinion should antedate Coster

D8's use of 12s that became the ubiquitous standard for Hague striking. I suggest that the chronology is

revealed by these hitherto unnoticed details. Evidently, Hague clock trains were still evolving, but the

cited similarities also dissimilarities cannot be random. Modern authorities say Coster did not make the

square-pillar timepieces, so was Coster instructing Severijn Oosterwijck to make his 'Coster' strikers?

20

<A1V7_D8strike.jpg>

D8 as found: Contemporary alarum is fixed on the IX side - necessitating the chopped-out recess.

Unlike Oosterwijck's RH, D9, his later clocks, "Salomon Coster" D8's swing-out dial is conventionally

hinged to its box-case - which case relates directly to Oosterwijck's RH and D9 box-cases.