Sinclair Harding H1

In May of 1714 representations from Her Majesty’s Fleet, Merchants and Merchantmen demanded the Government to encourage the solution of the Longitude problem and in July of that year the Longitude Act was passed offering up to £20,000 for a method of determining Longitude at Sea.

In the mid 1720’s Yorkshire born John Harrison started work on what would be the first of his clocks, the H1, that would work on board a ship to solve the Longitude problem. In 1772 after a lifetime’s work, culminating in the watch H4, John Harrison was paid the final balance of the £20,000 reward.

In 1999 Sinclair Harding started to work on a clock in homage of John Harrison. Nearly 5 Years in development, the Sinclair Harding H1 is a wonderful combination of art and fascinating mechanics, all finished to the exquisite standard.

To demonstrate the H1’s capability to work at sea the movement is mounted onto a granite base, which in turn is suspended on pivots. The whole piece sits on a table designed to the customer’s specification and is counter balanced by a massive weight. A tiny hidden DC motor rotates a small weight, which puts the whole assembly out of balance, and a gentle rocking motion ensues, creating a fascinating spectacle inside the elegantly engineered glass case.

Movement and Shade Height: 75cm Width: 76cm Depth: 55cm

H1 Movement finished in Gold on a Black Granite Base.

H1 Movement finished in Gold on a Black Granite Rocking Base, sat on a Rosewood Table

H1 Movement finished in Gold on a Star Galaxy Granite Rocking Base, sat on a Glass Table


Winding The Clock

The Sinclair Harding H1, unlike the original, is designed to be a practical piece and needs to be wound every 7 days, it will in fact go for nearly 8. A substantial cranked key winds the Fusee through a 2:1 step down gear ratio making the once a week experience almost effortless.


The power to drive the H1 is provided by 2 springs housed in barrels. The right hand larger barrel shown in the opposite picture, around which the cable is wound is empty and the spring is actually housed in the left hand smaller barrel. The cable drives a 2 start Fusee, carefully matched to the two springs and in order to ensure the escapement continues to operate while winding, maintaining power is provided to the Fusee Assembly.

No Friction

John Harrison was very clever and wanted to avoid using lubrication wherever possible. The arbors around which the springs are wound are mounted on rollers. On the Sinclair Harding H1, these rollers are positioned on the outside of the plates and if viewed carefully and be seen rotating very slowly.

Wheels N' Pinions

Harrison used wooden wheels and pinions throughout, using the Lignum Vitii, a wood which exudes its own oils. On the Sinclair Harding model, the wheels and pinions were purposely made in brass and polished steel. The interaction provide a fascinating spectacle and reflections from the plates and highly polished wheels serve only to deceive the observer.


All the parts on each clock are hand finished (even the ones you cannot see!). The Brass parts are protected with a thin layer of 23.5 carat Gold.

Our Tables are French polished, this technique produces a high gloss surface. We also offer a range of granite bases.

Walnut Burr


Black Granite

Star Galaxy Granite

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