Please identify this pocket chronometer

[BRIANWHALEY]

I bought this fusee chronometer today on it's way to the scrapper. I was approached by the owner to sell him a key so he could see if it ran befoe he scrapped it's 18kt. case. I grabbed it out of his hand, told him that I'd buy it and made the deal. Well, it does run and keeps accurate time, but I am unable to identify it. It only says "patent chronometer" on the movement. It does not have a helical hairspring. Any help would be appreciated

 

[MartyR]

I have a number of problems with what I can see.

First the hallmarks. I can't see a town mark which is very unusual (unless it's elsewhere on the case with another set of marks). The date letter (so far as I can make it out) is a cursive "D" and the only ones I can find like that are the Chester marks for 1729 and 1904, neither of which could be right for this watch. The maker's mark HW can only be for Henry Webb, a London maker who registered the mark from 1847 to 1879, and that date range could be about right for the watch.

Next, there is no maker's name on the movement (or on the dial, I assume). That is unusual for an English watch, and even more unusual for an alleged "chronometer". The use of the words "patent chronometer" on a watch without substantiation are, in my limited experience, exclusive to Swiss watches; more often than not the word "chronometer" has been used on such watches more in the literal sense than in the horological sense.

Do you see anything in the movement that suggests this is a horological chronometer?

It would be interesting to see photos of the dial and other parts of the case, to get a feel for the general quality of the watch.

 

[BRIANWHALEY]

Thanks for your reply. Here are some additional pictures of the watch

 

[Skutt50]

Could the Hallmarks be for London 1874.....?

 

[rodstan]

I think its more like London 1860 (small e gothic)
It is a lever chronometer for what its worth--chronometer = accurate timekeeper.
Not all chronometers are detents. Even Rolex chronometers etc are not detent escapements.
There may be more to the escapement than meets the eye, possibly a cut balance and quarter timing and mean time screws.
Nice watch
Regards
Rod

 

[MartyR]

The "new" set of hallmarks is fine. London 1860 as Rodstan says, which confirms the casemaker as Henry Webb. The previous photo was a partial set, but I still have no idea what that "cursive D" that I though I saw actually is

A watch is not a "chronometer" just because the maker says so. In common horological parlance it must have one or more of the features that are known to give a higher level of accuracy. Typically this means one of several forms of detent escapement, or a helical spring. Almost any decent quality watch of this date would have a cut balance, and I don't think timing screws would qualify for calling a watch a chronometer, would they?

I agree it's a nice watch, though

 

[DaveyG]

I think, to put Rods comments into context, I should point out that the definition of a chronometer has changed sowewhat over the years. Whilst many modern watches are defined as chronometers purely on their ability to maintain accurate time, in the period that this watch was produced I believe that it would have required the features that Marty describes with some variant of the detent escapement as 'mandatory'.

 

[jakraka]

Patent Chronometer could mean that the movement is equipped with a Robin type escapement according to the D. Morton's English patent No. 2432 of October 17th, 1857. The escapement is a combination of lever and detent escapements. There was a watch with this escapement also 'signed' Patent Chronometer (No. 1578) in the collection of the Time Museum. It is interesting to note that most of these watches utilising this type of escapement (London Patent Chronometer, Patent Union Chronometer or Patent Chronometer) have the same raw movement mark ‘H.F.’ (Henry Fletcher of Prescot). I wonder if the frame of this watch was also made by Henry Fletcher.

Regards

Jan

 

[jakraka]

At the first sight this escapement looks like a standard English table roller. And indeed the later versions utilise an escape wheel very similar to the standard ratchet tooth lever.

The patent abridgement: