Like many manufacturers, Zenith made timing instruments for the military. One I've been looking to add to my collection for awhile is the Zenith 8-Day Chronometer. The movement likely began as a clock for an automobile or other vehicle, but was up-jeweled from 6 to 15 as part of a partnership with Vail Watch Co. to supply marine chronometers to the US Navy during WWII. Enough with the history lesson...on to some photos.

Balanced on gimbals, the clock is mounted in a three tier box for protection:




Opening the first lid provides the viewer with glass-protected access to the time (top set of screws are not original)




The next level opens to allow access to set and wind the clock, as well as locking it in place.




The face shows some wear, but I choose to look at it as character. This was the seller's photo and doesn't do justice in showing how crisp the different colors look all together (blued hands, red day indicator, black numbering).




The back is weighted down by a sold chunk of brass that screws on. Once removed, the movement is revealed. You can see where the "6" in the number of jewels has been scratched off and replaced with "15." The serial number is 200368, but there is no caliber information under the balance wheel. I've seen a suggestion that it's a modified Caliber 271, but I never seen another example outside of these marine chronometers and the 271 isn't shown by Rossler or Ranfft. [EDIT - It is a Caliber 271, and a photo is on page 302 of Rossler]




And, finally, here's some source info from a book called Military Timepieces (and shamelessly borrowed from the internet)...



Thanks for reading to the bottom!

Mike

 

Very cool!

 

This is serious piece of instrument..........cool

 

Going to be hard to fit a strap to that Maybe a 24mm mesh?
In all seriousness though, it is a lovely timepiece.

 

Not such a far-fetched idea...
Have you seen Mike's wrist? I think he could pull it off.

 

Indeed, it's not that much bigger than a Montre d'Aéronef Type 20. Maybe those guys in the Ukraine can show me how to convert it.

Also, edit made to reflect that the movement is on page 302 of Rossler and is a Caliber 271.

 

Here's my new arrival. Outer box is a 7 3/8" cube on a 3/8" thick base with rounded flanges extending 1" out on left and right with small holes drilled through to secure the base to a fixed surface. A leather strap and brass buckle act as insurance for the small latch on the front.



Blue felt upholstery cushions the inner box, which is a 4 15/16" cube, with an upper lid revealing a glass window, and a lower hinge giving access to the chronometer, as Veritas99 describes.







The numerals on the dial are like those in the illustration above from Military Timepieces... a little different from Veritas99's example... note the pointy '4,' for example. This one also omits "8 Days" from the power reserve gauge, as the example in Military Timepieces seems to do. The crown at 12 o'clock sets and winds the clock, and the power reserve hand goes from "8 D'n" to "0 Up" as you wind her.



Heavy brass back to keep the clock face-up.



Nicely finished movement... not bad for a glorified car clock. And keeping good time over the past 12 hours.



Now to bolt it to my desk.

 

Don't forget the rule: when going to sea, never take two chronometers; it must be either one or three.
It wasn't possible to determine longitude without an accurate way to measure time.

 

Great clocks!

Here is a nice piece about the origin of the ships chronometer in the 18th century:

http://scheong.wordpress.com/2010/0...y-of-the-sea-clock-or-harrisons-chronometers/

 

As I understand it, they modified these automotive time pieces from 6 jewels (fine for a car that has the benefit of street signs to help determine longitude) to 15 jewels, to meet USN specifications.
One of those WWII "let's-beat-plowshares-into-swords" moments.

 

Nice marine chonometer......I always want to have one.

Not sure for what purpose, though..... .....

 

Lou, it appears you have not been paying attention to WRUW. He definitely needs one in his car.

 

I know ... having more than 3 wrist watches is definitely not practical.

 

Desk clock. Mantel clock. Kitchen clock. Bicycle clock. Hell, replace your microwave clock with one too.

 

Purpose? How in the name of John Harrison am I supposed to know where I am without this thing? Government satellites and smart phones? That's just the NSA telling me where they want me to think I am.::
But you're right, it's not worth squat without a sextant and some astronomical tables. And a boat... the horizon around here is too bumpy. Back to the 'Bay.