Display Watch

EW69 watch in box
watch index 27
country British  
piece name (title): Thomas Earnshaw Chronometer
set key
plate full
plate finish gilt
date 1807
case style pair
case material sterling silver
escapement chronometer spring detent
serial number 867
maker Thomas Earnshaw Senior was the inventor of the commonly used spring detent escapement and the fused metal compensation balance. His working addresses were 119 High Holborn 1794-1795 and 87 Fenchurch Street 1795 until his death in1829, after which his son Thomas continued the business until 1842.
movement Full plate, key wound, fusee with chain, the balance cock engraved with foliate scrolls. The top plate signed ‘Thos Earnshaw London INVT ET FECIT’ and ‘No 867’. The fusee is fitted with Harrison’s maintaining power.
escapement Spring detent escapement. The balance wheel has a diamond endstone and is in Z-form with trapezoidal weights with flat blue steel hairspring.
case The inner with plain polished back, the outer plain and apparently coated in dark paint.
case marks The outer case marked with a lion for Sterling silver, crowned leopard's head for London, M for 1807, and JP in rectangle for John Palmer, Clerkenwell, London, registered in 1807. The inner case marked with a lion for Sterling silver, crowned leopard's head and shield containing three wheatsheaves for Chester, L for 1807, and T.H incused for Thomas Helsby & Co, Liverpool, registered from 1739 to 1816.
dial and hands The white enamelled dial has a Roman hour chapter, closed minute ring to the outside, and a subsidiary seconds dial at 6 o'clock with closed chapter and Arabic numerals at 10 second intervals, with Arabic minute numerals to the quarters only. Two long hairline cracks.

The dial signed 'Thomas Earnshaw INVT ET FECIT No 867'

Gold spade and whip hands and a plain gold seconds hand probably unoriginal.
notes There appears to be an affix of some sort attached to each of the trapezoidal weights, whose purpose is unclear without a detailed examination. This may be a device to ensure that the balance remains in poise during adjustment, or a mechanism to prevent distortion of the bimetallic arms, again during adjustment of the weights, when the arms are vulnerable to damage. In the first case, the weights would have to be free to move radially during temperature compensation, and in the latter, the weights would need to be positively locked. The complete balance assembly is characteristic of an Earnshaw full chronometer.

The watch is contained in a mahogany case with hinged lid, and a key inset to the interior.
valuation This is a full chronometer deck watch by a famous maker in reasonable condition. The assumed original mahogany box enhances the value, but the cracked dial and unoriginal hands counter that.

No recorded sales of similar watches have been found, and this valuation has been based on the rarity, the quality and collectability of the maker, and prices achieved for chronometer deck watches by other reputed makers of a similar or later date.
copyright © 2017 Graham Morse and Martin Rosen
EW69 watch in box
EW69 case open
EW69 watch open case
EW69 back
EW69 back of inside
EW69 dial
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EW69 dial seconds
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EW69 works side
EW69 watch in box
EW69 fusee
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hallmarks in pair case
hallmark in case
repair person mark