Meridian calibre one # M-01 > The M-01 is the first hand-wound calibre from Meridian, a one-bench watchmaker: 21 jewels, 28,800 vibrations an hour, 72 hours of power reserve. Wind it, take it apart under the loupe, and reserve one of eighteen. 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, hand-wound | | --- | --- | | Diameter | 32.15 mm, 14¼ lignes | | Height | 4.90 mm | | Frequency | 28,800 vibrations an hour, 4 Hz | | Power reserve | 72 hours, one barrel | | Jewels | 21: balance 4, escape wheel 4, pallets 4, impulse pin 1, fourth, third, centre and barrel 2 each | | Escapement | Swiss lever, 15-tooth club-tooth escape wheel | | Balance | Ø 9.70 mm, glucydur, eight gold timing screws, free-sprung | | Hairspring | Breguet overcoil, twelve turns | | Going train | barrel 96 → 12 centre 80 → 10 third 75 → 10 fourth 112 → 7 | | Hands | Hours and minutes from the centre wheel, small seconds on the fourth | | Finishing | Perlage, 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 bench Delivery 01 January to March Kept by the workshop 02 January to March April 2027 03 January to March April 2027 04 January to March April 2027 05 January to March April 2027 06 January to March April 2027 07 April to June July 2027 08 April to June July 2027 09 April to June July 2027 10 April to June July 2027 11 April to June July 2027 12 April to June July 2027 13 July to October November 2027 14 July to October November 2027 15 July to October November 2027 16 July to October November 2027 17 July to October November 2027 18 July to October November 2027 --- The page this is the Markdown version of: https://meridian.laarpi.com/