Meridian calibre one

Meridian M-01

A hand-wound movement from a watchmaker with one bench. Twenty-one jewels, eight beats a second, three days of reserve. It is running now, on your time.

Power reserve

41 h 12 min

Wound by the workshop this morning.

Hold to turn the crown, or drag the crown on the movement. About forty turns from empty to full.

0 beats since you arrived

Taken apart, in the order it is serviced

  1. 100

    Mainplate

    1 · German silver, perlage ·

  2. 105

    Barrel bridge

    1 · Côtes de Genève ·

  3. 110

    Train bridge

    1 · three gold chatons ·

  4. 121

    Balance cock

    1 · with endstone ·

  5. 721

    Balance, sprung

    1 · eight gold screws ·

  6. 125

    Pallet bridge

    1 · black polish ·

  7. 710

    Pallet fork

    1 · two ruby stones ·

  8. 420

    Ratchet wheel

    1 · 50 teeth, snailed ·

  9. 415

    Crown wheel

    1 · 32 teeth, sunburst ·

  10. 425

    Click

    1 · black polish ·

  11. 180

    Barrel, complete

    1 · 96 teeth ·

  12. 206

    Centre wheel

    1 · 80 teeth, pinion 12 ·

  13. 210

    Third wheel

    1 · 75 teeth, pinion 10 ·

  14. 220

    Fourth wheel

    1 · 112 teeth, pinion 10 ·

  15. 705

    Escape wheel

    1 · 15 teeth, pinion 7 ·

  16. 401

    Stem and crown

    1 · fluted steel ·

  17. 5000

    Screws

    11 · heat-blued ·

  1. Screws first: eleven of them, heat-blued, every slot left at the same angle.
  2. The balance comes out under its cock. The train stops. No beat, no time.
  3. The mainspring is let down through the click. The reserve runs back to nothing.
  4. Pallet bridge, then the pallet fork with its two ruby stones.
  5. Ratchet wheel, crown wheel and the click that held them.
  6. Barrel bridge, then the barrel and the spring inside it.
  7. Train bridge, then the going train: centre, third, fourth and escape wheels.
  8. Stem and crown.
  9. What is left is the mainplate, perlaged where nobody but a watchmaker will look.

Finishing, under the loupe

Every surface of the M-01 is finished by hand, including the ones you will only see if you take it apart. Move the cursor over the movement anywhere on this page and it becomes a loupe.

Field 3.8 mm

i

Perlage

Overlapping circles ground into the mainplate with a turning peg, one row overlapping the last. They sit under the wheels, so they are there for the watchmaker who opens the M-01 in thirty years.

Grain 1.1 mm across, pitch 0.78 mm

Field 4.3 mm

ii

Côtes de Genève

Parallel waves ground across the bridges while they are screwed down together, so each stripe runs from one bridge into the next without a break. Each wave is a row of arcs left by the rotating peg.

Stripes 2.05 mm wide, laid at 58°

Field 1.9 mm

iii

Anglage

Every edge of every bridge carries a 45° bevel, filed and then polished to a mirror. A machine can round an outward corner. An inward angle has to be cut and polished by hand, and the bridges of the M-01 have nine.

Bevels 0.13 mm on the bridges, 0.12 mm on the cock

Field 3.4 mm

iv

Black polish

The click and the pallet bridge are polished flat on a tin plate until the steel is too smooth to scatter light. From most angles it looks black. Tilt it into the light and the whole surface turns white at once.

Click, pallet bridge, endstone cap

Field 3.1 mm

v

Heat-blued screws

Polished steel screws heated on a brass tray until the oxide film on their heads is thick enough to turn them blue. There is no pigment. The blue is light interfering with itself in a film a few hundred nanometres thick.

Nineteen screws, blued at about 290 °C

Back together, plate first

Meridian is one watchmaker at one bench. Each M-01 spends about eleven weeks there: six for finishing, three to assemble and regulate, two running on the timing machine.

  1. The mainplate, with six jewels already pressed in.
  2. The going train, each wheel dropped onto its pivot.
  3. The train bridge, coaxed down over four pivots at once.
  4. Barrel and barrel bridge.
  5. Ratchet wheel, crown wheel and click.
  6. Pallet fork and pallet bridge.
  7. The balance goes in last.
  8. Then the crown. It runs only once it is wound: wind it, or keep scrolling and the scroll turns the crown.

Specification

Calibre M-01, specification
CalibreM-01, hand-wound
Diameter32.15 mm, 14¼ lignes
Height4.90 mm
Frequency28,800 vibrations an hour, 4 Hz
Power reserve72 hours, one barrel
Jewels21: balance 4, escape wheel 4, pallets 4, impulse pin 1, fourth, third, centre and barrel 2 each
EscapementSwiss lever, 15-tooth club-tooth escape wheel
BalanceØ 9.70 mm, glucydur, eight gold timing screws, free-sprung
HairspringBreguet overcoil, twelve turns
Going trainbarrel 96 → 12 centre 80 → 10 third 75 → 10 fourth 112 → 7
HandsHours and minutes from the centre wheel, small seconds on the fourth
FinishingPerlage, Côtes de Genève, anglage with nine inward angles, black polish, heat-blued screws, gold chatons

The ratios check out: the centre wheel turns once an hour, the fourth once a minute, and the escape wheel sixteen times a minute, which with fifteen teeth and two beats a tooth is 480 beats a minute.

18 pieces in 2027

Eighteen M-01 will be made in 2027, numbered 01 to 18 on the barrel bridge. A deposit of €4,000 holds the next free number. It is refundable until finishing starts on your movement.

The watch is delivered in a 38.5 mm steel case with a sapphire back, for €36,000 including the deposit.

Numbers are given in the order deposits arrive. Number 01 stays with the workshop.

No.At the benchDelivery
01January to MarchKept by the workshop
02January to MarchApril 2027
03January to MarchApril 2027
04January to MarchApril 2027
05January to MarchApril 2027
06January to MarchApril 2027
07April to JuneJuly 2027
08April to JuneJuly 2027
09April to JuneJuly 2027
10April to JuneJuly 2027
11April to JuneJuly 2027
12April to JuneJuly 2027
13July to OctoberNovember 2027
14July to OctoberNovember 2027
15July to OctoberNovember 2027
16July to OctoberNovember 2027
17July to OctoberNovember 2027
18July to OctoberNovember 2027