Credit: Arnold & Son
The Arnold & Son True North Perpetual watch is a fascinating orchestration of moving parts that depicts the relationship between the earth, sun and time, including the equation of time, true solar time, mean (civil) solar time, second time zone and true north.
Unfortunately, this clockskin does not accurately depict all of those, but it does provide mean (civil) solar time (hours, minutes, seconds), month, date and power level (via the small triangular marker on the rotating silver bezel). The moon image rotates slowly (twice per day) and does not correspond to actual moon phase (except under the theory that even a broken clock is correct twice a day).
Clockskin Zip File download: Arnold & Son True North Perpetual (for Universal Launcher only)
If interested, this video (4 minutes) of my watchface (.watch version) provides a depiction of how the Arnold & Son True North Perpetual watch actually works.
See more of my watch face videos at my OnOurWatches YouTube channel.
6 Likes
Looks great! I’ll have a deeper look into it soon. Thank you for sharing! 
1 Like
Fantastic! Love the detail and understand the lack of “accuracy” comment as I have encountered the similar problems. I figure (correctly, I believe) that the important issue it that the watch is a great simulation for those of us who have these tiny interpreters of very complex watches.
Kudos!!
1 Like
@G1NT0N1C – I had a difficult time finding details online explaining how this watch dial works, specifically the two rotating bezels. With the help of a fellow watch enthusiast (who suggested this watch to me), we found the details I was looking for [I’ve summarized my understanding below from a longer explanation in a page of the watch’s Owner Booklet]:
The inner silver bezel rotates slightly clockwise or counterclockwise with the equation of time, using the markers at the top of the silver bezel [those markers are not at the top in the picture above because I changed its function to a power meter for the clockskin]. The triangular marker (normally near the bottom) is attached to this bezel. The outer bezel, for true north and true solar time, is user-rotated based on the user’s longitude, or more specifically, the difference between that longitude and the user’s time zone’s central longitude (a multiple of 15). Since this manual outer bezel rotation uses the inner bezel’s triangular marker for reference, the outer bezel is in effect adjusted for both longitude and equation of time, for accurate reading of true solar time using the outer 24-hour time scale.
The procedure for using the watch to determine true north is another story . . . To determine true north, the user sets the watch’s time to standard time (“winter time”) and goes outside at 12:00 noon civil standard time and points the blue sun hand towards the sun. Then the true north indicator will be pointing at true north (as opposed to magnetic compass north).
Well, at least the above is my understanding 
, reflected in the video linked above.