Results 1 to 3 of 3

Thread: Smiths techy question 2: Jewel counts

  1. #1

    Default Smiths techy question 2: Jewel counts

    I'm updating my Smiths group history ('The Golden Years') and thought it would be nice to include a simple table showing where all the jewels are on Smiths' various calibres:

    Ingersoll/Smiths-Empire 1-jewel rubbish
    Ingersoll/Smiths-Empire 5-J wristwatch
    Smiths 7-jewel stop-watch
    Smiths 1215 sub-secs: 15J, 16J Benson, 18J Garrard
    Smiths 27CS centre-secs: 17j
    Smiths Imperial: 19J
    Smiths Imperial auto: 25J

    recorded against:
    Centre (2nd) wheel
    3rd wheel
    4th wheel
    5th (escape) wheel
    escape lever
    - escape lever pallet stones
    - impulse pin
    balance staff
    additional end-caps
    (and which are deleted)

    A doddle - so I though!! How wrong could I be?! Even when working from a 15 jewel standard, I've been going round in circles trying to get them to tally as I'm ending up with a jewel short or spare!

    Can some kind soul put me out of my misery and tell me exactly where these jewels are in each SMITHS calibre, before I go completely mad!

    Many thanks!

  2. #2


    hmm I'll give it a go, but happy to have someone correct any errors:

    basic 15 jewel 12:15

    balance staff = 5 (cap jewels upper and lower + impulse jewel)
    palettes = 4 (pivot jewels upper and lower + acting faces x 2)
    escape wheel = 2
    fourth wheel = 2
    third wheel = 2

    total = 15

    Additional jewels for the others:

    16 jewel Benson = as 1215 + 1 x upper pivot jewel on the centre wheel
    18 jewel Garrard = as Benson + 2 x cap jewels on escape wheel (upper and lower)

    27.CS = as 15 jewel train + 2 x jewel for ss pinion (upper and one lower)

    Imperial 19J = as 15 jewel train +
    2 x cap jewels on the balance staff pivots
    2 x jewels on centre wheel (upper and lower)

    Imperial 25J = as 15 jewel train
    2 x cap jewels on balance staff
    1 jewel on centre wheel (upper)

    rest in the self=winding mechanism:
    2 x self winding ratchet (upper and lower)
    2 x swinging frame (upper and lower)
    2 x rollers
    1 x cam stud jewel

    Think that's correct, not sure about the Empire ones / stopwatch mind you!

  3. #3


    Thanks Crispin,

    I had been double counting end caps!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts