Mc Master (Dublin) rack lever converted to single detached lever

Discussion in 'European & Other Pocket Watches' started by John Matthews, Mar 18, 2017.

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  1. John Matthews

    John Matthews Registered User
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    #1 John Matthews, Mar 18, 2017
    Last edited by a moderator: Dec 29, 2017
    This watch was advertised as an early detached lever, but having recently acquired a rack lever, I recognised that it had two-way slides almost always associated with rack levers. The movement is now cased in an open face silver case hallmarked London 1848, with the makers mark of Richard Oliver & John Edwards, St Lukes, registered 5 June 1846.

    On receipt it was clear to see that the movement had been recased - the case being marginally too shallow for the movement. Examination has confirmed that the current movement is a single roller with a passing flat. It has a relatively short lever, which David Penney describes as a characteristic of the early single rollers.

    From what I can see this was initially a rack lever that was probably housed originally in a gold case. It was subsequently converted to a single roller, probably in the 1820s. At some point later the gold case was 'harvested' and was re-housed in the current silver case. The later casing may have been quite recent, I suspect after it was last serviced.

    The photographs shown that the movement has 2638 engraved on the underside of the cock and beneath the dial. It has the so called Liverpool arrows on the Bosley plate scale and has Liverpool jewelling to the fourth. The style of the cock is most similar to those signed by Robert Roskill (I have compared it with his 7684 & 8394), rather than Paul Litherland. It would be nice to suggest that the number is that of Roskill which would date it as c1804 - but this would be pure speculation. All that can be said with certainty is that it has all the characteristics of a converted Liverpool finished rack lever.

    John

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  2. gmorse

    gmorse Registered User
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    Hi John,

    Very good pictures of an interesting conversion.

    There is the slightest hint of a curve, as though whoever converted it couldn't quite make their mind up whether to make a crescent or a flat. They also apparently got one banking pin wrong when planting it, having to bend it later. The lever has straight sides, which reinforces the thought that it's relatively early.

    Regards,

    Graham
     
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  3. John Matthews

    John Matthews Registered User
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    Hi Graham - You are right it does appear from the photographs that there could be a slight curve, I didn't notice it when I inspected it with the lens. I thought it was planar, I will have to check next time I remove the cock.

    Initially, I though the banking pins were left over from the rack and were bent to accommodate the lever - but you don't have banking pins with a rack do you, so as you say the one was incorrectly positioned on conversion and had to be modified to accommodate the swing of the lever.

    Regards

    John
     
  4. Omexa

    Omexa Registered User
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    Hi John, a Rack lever does have Banking Pins. Regards Ray
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  5. gmorse

    gmorse Registered User
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    Hi John,

    Ray's right, and the pins are typically planted inboard of the lever arbor.

    Regards,

    Graham
     
  6. Lychnobius

    Lychnobius Registered User

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    It is interesting that both the dial-plate and the movement bear a serial number (2638) which is different from that on the barrel-bridge (1170). I have often wondered whether the serial numbers on what I call badge-engineered movements, i.e. those which were made for rather than by the person whose name appears on the barrel-bridge, were applied by the signatory (the retailer) or by the actual finisher. Often, when a five-figure number appears on a movement 'made' in a mere village, it is difficult to believe that this number belongs to the retailer; here, on the other hand, it looks as if McMaster of Dublin has assigned his own number. Perhaps the retailer had a free choice in this matter.

    Straight-sided levers seem to have died out in about 1860.

    Oliver Mundy.
     
  7. Jerry Treiman

    Jerry Treiman Registered User
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    I know that we do see some rack levers with banking pins, but is this really normal? My two examples do not, and it seems awkward to have them. Since this is not a detached escapement, the banking could cause a jarring stop to the balance rotation. However, I see that it could also prevent the pallets from engaging too deeply with the escape wheel. Neither action seems too favorable.
     
  8. Allan C. Purcell

    Allan C. Purcell Registered User
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    Just reading your old thread John, I agree with you that 2636 could be a Roskell number, and another way of converting Racks to STR was just to plant the Lever arm into the slides. I have two of them, and they work fine. Allan
     
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