Brockbanks, London

• Movement: gilded full plate, Peto’s cross-detent escapement, jewelled wheel train, three-arm balance with three bi-metallic rims each with travel limit screws, highly
polished steel weights with lateral and timing screws, blued steel helical spring, balance cock engraved with trophies of war, ruby endstone, signed Brockbank’s, London, no. 641
• Dial: white enamel, Roman numerals, large subsidiary seconds, gold spade hands, signed Brockbanks, London
• Case: silver case, fixed cuvette, plain polished back and bezel, the pendant with split push piece for releasing bezel and back independently, case back hallmarked 1807 and with maker’s mark TC for Thomas Carpenter

Terence Camerer Cuss, The English Watch 1585-1970, 2009, p. 342, pl. 217

Movement running at time of cataloguing and appears to be in good clean condition, winds and sets. The dial appears to be in good condition. Catch for front and back bezels through the split pusher in the pendant all operational. Covers close securely. Case in good condition.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. All dimensions in catalogue descriptions are approximate. Condition reports may not specify mechanical replacements or imperfections to the movement, case, dial, pendulum, separate base(s) or dome. Watches in water-resistant cases have been opened to examine movements but no warranties are made that the watches are currently water-resistant. Please note that we do not guarantee the authenticity of any individual component parts, such as wheels, hands, crowns, crystals, screws, bracelets and leather bands, since subsequent repairs and restoration work may have resulted in the replacement of original parts. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. In particular, please note it is the purchaser's responsibility to comply with any applicable import and export matters, particularly in relation to lots incorporating materials from endangered species.NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

**Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping."

The movement of this watch incorporates James Peto’s cross-detent escapement which research suggests was introduced in the late 1780s. James Peto (active c. 1780- 1800) was an employee of the Brockbanks and invented his variant of the spring detent escapement. It combined Arnold’s in-tension detent and Earnshaw’s impulse, but had
high inertia causing considerable friction between it and the passing spring, and the use of oil was necessary. Earnshaw, who himself had worked for the Brockbanks, accused Peto of deliberately altering his own (Earnshaw’s) spring detent escapement to evade Wright’s patent of Earnshaw’s spring detent escapement (see lot 39). Earnshaw accused Peto of acting with the encouragement of the Brockbanks. For an examination and discussion of Earnshaw’s account see Vaudrey Mercer, John Arnold & Son, 1972, p. 90-92.

The brothers John and Myles Brockbank used Peto’s crossdetent in several of their watches. Interestingly, as Cecil Clutton and George Daniels pointed out in their book, Watches, “Breguet thought so well of it [Peto’s cross-detent] as to introduce it into at least two of his finest tourbillons made after 1810” (see op. cit. 1965, p.144 and figs. 39 & 407-408). Peto’s cross-detent, as seen in the present watch, has a very pleasing
action and is complimented by the impressive balance with its highly polished steel weights.

A diagram of Peto’s cross-detent and illustrations of Brockbanks’ distinctive balances, can be found in the two-part article of the firm by F. von Osterhausen, Antiquarian Horology, September & December 2001.

For a note on Brockbanks, see lot 44.