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Watch and instrument makers, of Trafalgar Sq, London
1873 Samuel Smith, Junior opened larger premises on The Strand and later had shops in Piccadilly and Trafalgar Square in London
1882 Listed at 151/153 Newington Causeway as Watchmaker and Jeweller. 
1884 Listed as 'Smith Samuel goldsmith, jeweller, optician, watch maker and jet ornament manufacturer. 151 and 153 Newington Causeway' 
1895 Listed as Samuel Smith, Watchmaker and Jeweller of 151 and 153 Newington Causeway 
1898 'Smith Samuel and Son, 9 Strand WC; watchmakers to the Admiralty, high-class watches with certificates from the Royal Observatory, Kew; premier positions 1885 to 1898; medal for non-magnetizable watches; split seconds chronographs; sole makers of the four-dial non-magnetic chronographs and revolving escapement watches.' Also one line entry under jewellers. 
1900 At the start of the 20th century and the age of the automobile they produced the first British odometer ("mileometer") and speedometer.
1913 April. Advert in Autocar for Speedometers. S. Smith and Son of 9 Strand, London. 
1914 Advert for S. Smith and Son wrist watches gives addresses at Trafalgar Square and 68 Piccadilly 
1914 A public company S. Smith and Sons (Motor Accessories) Ltd was formed to acquire from S. Smith and Son that part of the business concerned with manufacture of speedometers, carburretors, and other motor accessories with headquarters at Great Portland Street. The company was run by Samuel Smith Junior's son Allan Gordon Smith and the turnover was more than £100,000.
1919 Advert: Watches and Jewellry
1921 Made an astronomical clock-watch for an American client.
1931 Robbery at the shop of S. Smith and Son (1929) Ltd, 6 Grand Buildings, London W C
Also see Smiths