A VERY RARE W. EHRHARDT MILITARY POCKET WATCH SIGNED 4 TIMES Date: Circa 1920's Movement: English lever with "replaceable balance assembly", full plate unusual construction marked with broad Military arrow, polished steel regulator, compensation balance with blue steel over coil hairspring, English table roller lever escapement Dial: Signed, white enamel, Arabic numerals, blued steel hands, subsidiary dial for seconds at the 6 o'clock position Case: Signed "S.M Co Ltd" and "W Ehrhardt London", silver open face with single hinged cover, Hallmerked Chester 1920,screw down bezel, screw down back Size: 50mm * Case, back, movement engraved D69934 *The same watch is mentioned in the publication  MILITARY TIMEPIECES by  Z.M.WSOLOWSKI pp. 21 The purpose of this unusual construction is said to be the need to service the watch in the field. Should the balance staff be broken (which would have happened frequently in military use) it could easily be replaced with a new timed assembly and put into beat by unskilled personal due to the design of the cock. William Ehrhardt opened a workshop at 30 Paradise Street, Birmingham in 1855 and in 1862 opened a second manufacturing premise at 26 Augusta Street. From this second address he exhibited watches and instruments at the 1862 International Exhibition in London.The firm moved to larger premises at 72 Great Hampton Street in 1863, and later to Time Works, Barr Street. By 1880 the firm was manufacturing 500 watches a week, some by hand and some by machine because William was fair minded and appreciated that some of his older staff preferred to work with the old methods.  By 1898, a shop had been opened in London at which time they advertised that they made 500 patterns in gold and silver ranging in price from œ8 to œ25 and œ1.5 to œ5 respectively.