Review: Oestmann: Heinrich Johann Kessels

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Fortunat Mueller-Maerki

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Sep 23, 2001
First published in the March 2012 issue of ANTIQUARIAN HOROLOGY, The Journal of the Antiquarian Horological Society, UK
Reproduced on this Message Board with their permission

Biography of German Chronometer Maker H.J. Kessels

Heinrich Johann Kessels (1781-1849) – Ein bedeutender Verfertiger von Chronometern und Präzisionspendeluhren, (Heinrich Johann Kessels – An important maker of chronometers and precision pendulum clocks). By Gűnther Oestmann; published in German, in 2011 as Volume 44 of Acta Historica Astronomiae, by Verlag Harri Deutsch, Frankfurt am Main (Germany). Paperback, 274 pages, 21 cm high x 15 cm wide; approx. 65 illustrations (incl. 2 in color and 2 foldout plates), bibliography. Available at for approx. Euro 25 plus shipping.

Kessels, born in the part of Holland that later became Belgium, a student of Breguet in France, later a Danish citizen, who practiced primarily in Altona (Hamburg, Germany) was one of Germanys best –if not the best- Chronometer makers in the first half of the 19[SUP]th[/SUP] century. While virtually unknown in most horological circles in the English speaking world, he is an icon among chronometer aficionados and those interested primarily in observatory-grade, precision pendulum clocks. Up to now however there was no scholarly publication documenting his life and his oeuvre. That has changed with the book under review.

Gűnther Oestmann started his professional life with an apprenticeship as a watch- and clock maker, then studied art history and the history of science, earning his Doctorate in 1992. His subsequent career has oscillated between academic appointments, teaching the history of science at various German universities, practical work as a clockmaker, scholarly writing, and curatorial museum appointments. His recently published book on Kessels originally was conceived as a chapter in a much larger (and soon forthcoming) grant funded research publication on the history of the introduction of the chronometer into both, Germany’s navy and its merchant fleet. The huge amount of Kessels related material unearthed by the author made it advisable to turn that planned chapter into a stand-alone monograph.

Kessels biography (some 25 pages in the book) shows that he was a man of many talents: As a young man he may have been involved in designing tower clocks, he worked first in a yet unidentified British location, then for several years in an also unidentified ‘very significant shop’ in London. From January 1815 through May 1821 he mainly worked for the Breguet workshops in Paris. The surviving Breguet workshop records document that he worked on over 140 timekeepers for Breguet, including tourbillons, repeaters and chronometers, as well as many legendary objects (like the Marie-Antoinette pocket watch). One of the appendices in the book under review provides the exact dates Kessels worked on each of the approximately 140 Breguet watches listed, in some instances describing the work undertaken.

In the early 1820s Kessels moved to Hamburg, where recently an observatory had been built in Altona; for many years he lived and worked close by. By 1830 he had become a citizen of Denmark and his main products were marine chronometers (both box chronometers and pocket watches with chronometer escapements, i.e. observation watches), as well as pendulum clocks for astronomical observatories. Friederich VI, King of Denmark, was a patron of the sciences and provided partial funding for building marine chronometers ‘on speculation’, without firm orders. Once completed the Altona observatory certified their rates, making these marine chronometers very desirable. Kessels often also acted as an agent of Breguet in Northern Germany and Scandinavia. There also seems to have been some sort of cooperation with the British chronometer maker George Muston (London and Bristol). Furthermore Kessels was a sales agent for domestic tallcase clocks originating from Bornholm island.

Kessels numbered his clocks, Numbers 1, 3 and 268 are documented, and then there is a gap with No. 1252 being the next confirmed number. It seems likely that all (or most) of the numbers between 1252 and 1448 were actually made, resulting in a total production of about 200 to 250 precision timekeepers. As Kessels died in 1849 of Cholera during a trip to England, he seems to have produced an average of around eight high grade clocks per year.
The next section of the book (10 pages) discusses the technical characteristics of Kessels’ clocks.

This is followed by the core of this book: A scholarly catalog of his oeuvre (78 pages) describing 82 numbered timekeepers on which Oestmann found some documentary evidence. Of these 82 he has been able to track down the present whereabouts of 44 items. On the 38 ’lost’ items the author quotes verbatim the often historic documents describing the clocks. For most of the 44 others there are is a longer description, usually including b&w photographs of cases, movements and dials. A short addendum to the main catalog includes descriptions of two clocks by other makers that were significantly modified by Kessels, and 17 unsigned, unnumbered pieces classified as probably originating from the Kessels workshop.

The biggest section of the second half of the book is devoted to reproducing 19 pieces of documentary evidence relating to Kessels which were discovered by the author (64 pages). This includes: Three early letters by or to Kessels; a letter of recommendation for a departing employee; the section in Moinet’s horological treatise dealing with Kessels; a letter by Urban Jűrgensen to the Altona Observatory discussing Kessels work; transcripts of two pricelists (dated 1826 and 1828); a hereto unpublished exchange of nine letters (1837-1845) between Kessels and Prof. Benzenberg, a German astronomer, discussing the merits of various timekeepers for observatory work; a set of unpacking and installation instructions for an observatory regulator; the transcript from the archives of a Russian observatory, concerning five interactions with Kessels (1830 to 1909); and finally a full transcript of all mentions of Kessels’ work in the Breguet shop records (1817-1821, sorted by Breguet serial numbers, dealing with over 140 different Breguet items).

This is followed by facsimile reproductions of various historic publications about Kessels, including: 1.- The rate sheet from the Kessels precision pendulum clock No.1342 by the US Naval Observatory; 2.- Pages 322 to 331 (plus 7 plates) of ‘Schauplatz der Kűnste, Vol. 151 (Weimar: 1856)’, discussing a new precision pendulum clock of Kessels; 3.- a 6 page facsimile extract from Hansen (Altona: 1836): Ueber die Chronometer, including care instructions and price lists for Kessels chronometers; 7.- A list of letters from and to Kessels which survive in various archives (Oslo, Marburg, Berlin, Düsseldorf, Bremen and Bonn). This reviewer was pleasantly surprised that those documents not originally written in German reproduced in this section were presented both in their original language (Dutch, French or Danish) as well as in German translations, allowing readers who know the languages to pursue the original version. The final 27 pages of the book are taken up by an extensive bibliography of 264 different consulted sources.
* * *
This reviewer doubts that any reader will read this book cover to cover, but that is not the point of either a ‘catalog’ –which is the core of this book- or of most scholarly publications, especially if they extensively quote original source documents. The biography section up front will be enjoyable and informative reading for most readers, but the catalog and the documentation by necessity are more a reference work than a readable book.
A review of a foreign language book appearing in an English language publication also needs to address the value of the book to a reader who does not understand the foreign language: Assuming that such a reader has both a fair prior knowledge of the general subject matter, as well as a keen interest in the subject, this reviewer feels strongly that the language barrier usually does not present an insurmountable problem. Firstly because the book contains some 60 interesting pictures, but more importantly because –especially in a catalog- the vocabulary is relatively limited and repetitive. In addition todays electronic tools, like ‘Google translate’, can produce decipherable translations that with some creative effort can usually be understood.

Oestmann’s Kessels book, in spite of its narrow and specialized subject matter is a most valuable and important addition to horological scholarship and the horological literature. The horological community should be thankful that there are scholars out there willing to tackle such projects, and funding agencies willing to approve grants to support this kind of research. Thank you Gűnther Oestmann, and thank you Deutsche Forschungsgemeinschaft. Your readers know that these kinds of publications exist only due tour selfless efforts, and not because there is a viable commercial market for such books.

Fortunat F. Mueller-Maerki, Sussex NJ (USA)
26 October 2011


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