This is a very early example of the first portable watchman's clock, invented by Johannes Bürk in 1855. This one was produced with a porcelain face and is in a
soldered brass case in which is scratched "21 October 1861," which is presumably a repair date
The marking "J. BÜRK PATENT" is not known to have been used by Bürk. Because of that
and the location of the winding arbor, Werner Schmid, of Stuttgart, who knows of a clock in Germany with the same marking and who has considerable familiarity with Bürk history, believes this clock is a
counterfeit. That is more than likely the case. However, the aberrant location of the winding arbor and this particular marking, J. BÜRK PATENT, may date from a period before the characteristics of Bürk's
production became fixed. Under this hypothesis, the patent referred to may be Johannes Bürk's American patent of January 1, 1861, which he assigned to his brother, Jacob E. Buerk in Boston. As the marking
meant little in Europe and was of value only in the American market, perhaps Jacob added the marking in Boston.
Starting at an unknown date in the early years of the Bürk firm, these clocks began to be
serially numbered and to be marked "J. Bürk Original" (in script). Somewhat later, the movements are impressed with a trademark consisting of a chapter ring circumscribing a monogram for the name
of the firm, Württembergische Ührenfabrik Schwenningen.
These clocks were produced to an amazingly uniform design through at least 65 years represented in the Detex Collection, that is through number
74,885 (1921). The most obvious alterations were in fabrication and markings of the face dial and, in later years, use of platform escapements. A detector mechanism was added (a spring to mark the chart when
the cover lock is actuated). Escapements vary, but throughout the movement is almost invariant, and the chart drum rests on and is carried by the hour hand, in the absence of a minute hand. The standard unit had a
drum for six stations, as shown here. In Europe, but apparently rarely if at all in America, models with drums for 12 and for 18 stations were marketed.
Within five years of introduction of the
drum clock, J. E. Buerk of Boston persuaded his brother to produce for him a much simpler clock using a flat, disk-like recording chart instead of the more expensive design with the turned recording drum.
See I.D. 383. That set the direction followed by all other makers (except for tape clocks in later years) and held down sales of
the "Original" in the U.S.A.
Key post, spring fingers, paper strip, and detector spring that marks strip to record openings and closings of cover. [I.D. 59]