Friday, November 13, 2009

Rectangular Watch Proportions

I like vintage rectangular watches, popularized by Cartier in the form of their famous "tank" watch. Have you ever wondered how watch designers come up with the proportions, e.g. dial width x height, used in that kind of watch? After all, a rectangle can be virtually a square or, at the other extreme, almost a line! Surely their bosses didn't just say "draw me a dial for our latest answer to le tanque"?

The literature of Art and Architecture makes much of the importance of correct proportions. It turns out that the most referred-to proportions have been popular since the time of the ancient Greeks. The Greek philosophers, in particular Pythagorus, spent a lot of effort on the subject of geometry. They arrived at a set of pleasing proportions that can be created using simple geometric figures and therefore by ordinary drawing instruments.

Could a geometric method have been used by a latter-day draftsman to construct his dial drawing ready for use by the screen-printing department?

Pythagorus came up with three kinds of proportions: Arithmetic, Geometric and Harmonic. You can read more about those here. These proportions or "means" can be calculated but, more importantly, they can be drawn using simple drawing instruments such as rulers or compasses. If we were to consider the numbers 1 and 2 and find out what the three possible means are, that would give us three easily-drawn ratios. They work out as follows:

3 by 2The arithmetic mean of 1 and 2 is 1.5, a proportion of 2:3. Easy enough to draw: Make a square and divide it into quarters. Draw a line through the diagonal of one of the quarters and continue until it meets the extension of one side of the square (see construction at right).

1 by root2The geometric mean of 1 and 2 is 1.414: Draw a square with a side equal to the required width. Then use dividers to measure the diagonal and use them to mark the required height.

4 by 3The harmonic mean of 1 and 2 is 1.333. To be exact, it's 1-1/3 and can also be represented by the proportion 3:4: Split a square in two and then split one of the resulting rectangles in two along it's length and "remove" the outer part.

Be that as it may, I then measured the aspect ratios of the outside edges of the watch dial minutes chapters for which I have pictures. I measured the chapters because these are probably both the starting point and the main feature of any dial design. I leveled them up in PhotoShop and then measured the minutes chapters width and height in pixels. Dividing the height by the width gave me an aspect ratio, i.e. the proportional mean. Whilst bearing in mind experimental errors with this method, here are the results:

These two have the arithmetic proportions; the Jurgensen measured at exactly 2:3
3 by 2gilmanjurgensen

This one was close-ish to geometric at 1.39:
1 by root2bulova

This one was exactly harmonic:
4 by 3bulova

These non-pythagoreans came in at an easily drawn 1.25 which, by the way, is a popular aspect ratio for photographic printing, e.g 8 by 10:

5 by 4curvex deco

The one below, at 1.7, looks skinny and appears not to fit any known arty-crafty criterion, not even the oft-quoted golden ratio. However, 1.7 is extremely close to 1.666, i.e. a proportion of 3:5 which can be drawn similarly to the previous method:

5 by 3gruen

Note also that the numbers 3,5 are sequential members of the Fibonacci series which, at it's limit, does indeed equal the Golden Ratio.

I conclude that many designers used easily-drawn geometric proportions for dial art-work but did not necessarily adhere to just the three classic Pythagorean means. In Japanese architecture, rooms were often sized by the fit of standard tatami mats which themselves were 3ft by 6ft i.e. 1:2. Different arrangements and numbers of mats used resulted in various proportions, including our 2:3, 3:4 and 4:5 but apparently not 3:5. However, the Italian architect Andrea Palladio (1508-1580) did include the proportion 3:5 in his "The Four Books on Architecture" as one of the seven "most beautiful and proportionable manners of rooms". Not to be outdone, the 20th century French architect Le Corbusier came up with a "Modulor" tool that allowed the drafting of dimensions that were all proportioned according to the Golden Ratio.
Best regards,

Tuesday, October 13, 2009

Re-painting bezel markers and watch hands

It's not too hard (assuming that the bezel marks are engraved). Use Tesors or Humbrol modeling enamel and some really good quality fine artist's brushes. Here's my Longines Weems bezel, before and after.

Paint the marks and numbers, doesn't matter if you go over the edge of the engraving. Wait until the paint gets tacky. Wet, but do not soak, a cloth in thinners or acetone. A nap-free cloth is best, e.g. an old cotton shirt. Wipe the bezel quickly one time in a circular motion around it (to cross the markers, not run along them). Don't press too hard i.e. you must let the solvent remove the excess enamel rather than scraping it off with the cloth. Don't go back and try to remove the inevitable smear or two. Wait for the paint to dry, preferably overnight. Then remove the smears, again with a one-shot quick motion. If you have go over a smear again, wait for for the solvent/enamel to dry completely before wiping again.

Hands are best removed, wiped with solvent and then mounted (upside down for hours & minutes hands with missing lume) onto cocktail sticks pushed into a lump of Rodico. You have to work fast, not allowing the enamel to dry. You might want to thin it just a little. The enamel must flow from the brush onto the hand. Put some enamel in a cap. Don your jeweler's loupe, pick the finest brush you've got and load it with enamel. From the base of the hand outward, run the brush along in ONE stroke. Do NOT go back and re-touch it. If it doesn't look right, remove the paint immediately and do it again.

A little practice before helps a lot!

Best regards,


Friday, August 14, 2009

Removing/Replacing a Gallet snap-back

These military backs are really hard to remove. If you do manage to struggle one off, putting it back on ain't that easy, either. I'm sure that there are proper tools out there that will do the job perfectly but, if you're brave, here's how I do it.

First, using a small screwdriver or a plastic cocktail stick, put a few drops of your favorite penetrating oil around the join and leave it for a few hours.

This is the business end of my Dad's old mortising chisel. The blade section is about 7/16" square and the tool is about 18" long. The end will need a quite shallow bevel, less than that of a properly sharpened chisel.

mounted in vise
Place the watch in a vise, which must have soft alloy protectors on the jaws or, better yet, medium hard plastic ones. Tighten the vise just enough to prevent the lugs opposite the chisel from riding up the jaw under pressure.

mounted in vise
In this view you can see that the back does have a slight chamfer that the chisel blade can contact. Sometimes, the gasket is not fully compressed and there's a small gap to allow the blade to insert itself further.

chisel in operating position
Ignore the photo above, I don't push on the lug any more. Instead, I rest the chisel on the vice jaw, making quite sure that it is not going to bear on the strap bar. Push the chisel firmly forward into the chamfer on the underside of the snap-back and lever the chisel handle downward. The back can fly off with a loud ping, so arrange that it can not land good side down (like toast) on your hard uneven concrete floor.

crown stem detent
If you need to remove the movement, push the little button while pulling on the crown

A woodworker's clamp can be used to refit the back to the watch.

press setup
Put a very thin coating of grease around the spigot on the body where the back fits. The PVC pipe connector fits over the bezel but does not press on the crystal. The scrap plastic plug presses on the inner part of the back - the theory being that the back might flex enough to open out it's edges a little.

press setup detail
Tighten the clamp slowly, all the while making sure that parts stay as parallel as possible. I find that pressure builds up and up - and then the back just slips on. Make sure it is even all the way around. Move the plug over and re-clamp if one side of the back is not all the way on.

Y'all be careful now and don't force anything!

Best regards,

Sunday, June 28, 2009

Lume wabi-sabi, is it good or bad?

When a reference is made to wabi, it is usually made with respect to the external aspects of a watch - a dinged-up body, scratched crystal, a repair and so forth. The word itself derives from the Japanese phrase wabi-sabi, see Wikipedia here.

"Wikepedia" wrote:

Wabi . . . . . can also refer to quirks and anomalies arising from the process of construction, which add uniqueness and elegance to the object. Sabi is beauty or serenity that comes with age, when the life of the object and its impermanence are evidenced in it's patina and wear, or in any visible repairs.

Which brings me to lume on old watches. Here, utility conflicts directly with sabi, because most old lume doesn't glow much, if at all. Radium itself lasts a long, long time, but it's radiation does kill the phosphor in most paints of the era. Promethium barely lasts a couple of years. Tritium lasts longer but is still getting quite faint after 20+ years. Now some people want their lume to glow, whatever the age of the watch, and often have their watches re-lumed with modern stuff like SuperLuminova - while others consider that to be heretical. Here's a couple of 80 year-old watches that illustrate the difference:


At left is a re-lume using what looks like Luminova, color code C3 green. At right is the same model with it's original lume, a sort of faded mustard color.

Both have wabi, the lume having been applied by hand. At left, there is also a little sabi because a re-lume is, after all, a repair. At right, sabi positively abounds, IMHO: the fading of the lume color, the pieces of lume missing from the hands, the different hue of the lume on the hands.
I prefer the one on the right, which is a good thing because it's from my collection ;-)

Best regards,


Monday, May 25, 2009

Hamilton 987 movement revealed

Modern movements are mostly mass-produced - in fact, it has been said that some are untouched by human hand.  While the technology and the use of exotic materials has progressed indeed, there is something enduring about a movement made the "old-fashioned" way.  In the first half of the 20th century, Hamilton was in the forefront of American watch manufacture.  This 987 movement was made at the very beginning of the Great Depression.  Although it is a production-line movement, it does show considerable attention to detail.  The size is 6/0 which makes it just about 1" diameter (see a good explanation here).

body dialside
The dial side of the body is decorated with pearlage, done by hand.  The serial number 4092105 dates the movement to 1929 or 1930.  There are three holes for the dial posts as opposed to only two on later movements.  The cross-headed brass heads are for adjusting the lever banking pins.  The balance pivot cap jewel can be seen just below, held by two tiny countersunk screws - later movements use just one.  On the minus side, there is an off-center staking on the pallet pivot jewel and the balance pivot cap seems to have taken a hit :-(

body topside
The top side is also decorated with pearlage.  The banking pins are eccentric which allows the banking to be adjusted merely by turning the screws - instead of the tedious shaving or staking used on modern watches where the banking is formed as an integral part of the pallet bridge.  Other watches have bendable posts which can snap and, when bent, become out-of-square with the pallet lever unless you do it correctly which is really, really difficult.

Here we see the côtes de geneve decoration on the bridges.  The machining on the two wheels is beautifully done with beveling and undercutting plus that nice helical effect.  Not sure of the correct term but it's done by scribing from the center radially outward while the wheel is turned at constant speed.  The jewels are held in chatons, including the center-wheel jewel which is quite unusual.  The engraving was filled with black enamel originally, most of it gone now.

keyless works
The keyless work is simplicity itself and shows it's pocket watch origins - no pesky wire springs or pressed tin here!!  The minute wheel shows little sign of wear for a 80-year old watch.

pallet lever bridge
The pallet lever bridge is shaped symmetrically and the stamped numbers match the serial number marked on the movement body.  These movements are from an era when parts were tweaked to fit together during manufacture, as opposed to being assembled from fully interchangeable parts.  Hence the need to match numbers in a similar way to other machinery such as handguns or rifles where "matched numbers" are de rigeur.

pallet lever
Sorry about the poor shot of the pallet lever.  The lever is pretty plain compared to the rest of the movement - no beveling, for example.  The shaft appears to be bent but it will be left as-is.  It is so easy to "repair" a perceived problem only to find that the movement stops working!  So, unless escapement mis-locking occurs, it will be left alone.

balance and cock
The balance cock is held firmly in place with three posts as opposed to the more modern two.  The hairspring is of blued spring steel and, as such, is affected by temperature.  This is offset to an extent by the temperature-compensated bi-metallic balance rim.  The rim also has four timing adjustment screws; there is a small scratch on one of the arms where someone slipped while making an adjustment.  Matching numbers, of course ;-)

Best regards,


Friday, May 22, 2009

Art Deco on an eBay Hamilton

Saw this nice-looking Hamilton on eBay and was lucky enough to win it. When it arrived the Art Deco influence was quite obvious. The phrase "Art Deco" was derived from a 1925 Paris exhibition - the "Exposition Internationale des Arts Décoratifs et Industriels Modernes" - see here for more about that. Art Deco succeeded the Art Nouveau movement which was full of natural motifs e.g. vines, flowers and leaves and such. This watch dates from 1929 or 1930, according to the 987 movement serial number.

Above we see a square watch body, softened by rounded corners. This follows the Deco style of using basic geometric figures. This body style is repeated both in the minutes and the seconds chapter rings. However, the hands and the blocky hour markers owe more to the first world war than to the Art Deco movement, I think. Also, the Hamilton logo font itself is more reminiscent of the late industrial 1800's.

However, Art Deco returns when we move to the seconds sub-dial. The long markers and the angled fonts combine to form an implied 'sunburst' effect. The effect fails to an extent, because the font does not expand outwards which is why I say "implied". In this close-up view of the dial screen-printing it is clear that the technology of the time has room for improvement.

In this angled view, we see the parallel linear motifs on the side of the body, the motifs being very common in Art Deco - mimicking radiator grilles, speaker grilles, stiffening ribs on aeroplane skins and other 'modern' looking stuff.

Here we see another view of the side showing the 3 lines which are actual formed by a groove in the body and the two lines where the body joins with the bezel and the caseback.

Another popular Art Deco motif is the "ziggurat" which means a form whose cross-section is that of a staircase. Here a ziggurat is plainly visible on a lug. Ziggurats are found on other watches of the period, more usually in the form of step-sided bodies - a device to accomodate round movements into rectangular bodies, viz. Bulovas.

This watch was not running when received. However, while taking these pictures, it got dropped on the bench and has been running well ever since!

Best regards,


Sunday, April 5, 2009

Aerospace Update

Some time back I was less than complimentary when comparing a newly acquired (eBay) Breitling Aerospace to the trusty Citizen Wingman, See here.

Well, after I worked out that I can set it to local Solar time and still have Central Daylight time on the LCD, I began to warm to it a little. But somehow after making that adjustment, the hands would show up slow to the sun after a day or so. The LCD was still spot-on to the atomic clock over the bench, so off with Aerospace and back on with the trusty Wingman. This went on intermittently for a week or two, until finally I saw a minute pass by on the LCD but no corresponding tick on the minute hand. I have to say that I got seriously pissed-off at my almost $800 eBay bargain (sob).

However, close examination with a loupe revealed a rub mark on the hour hand. So I took the movement out thus:

You take off the strap and put the watch upside down in a vise. The lugs are held firmly near the top of the aluminum-lined jaws. Then take your Dad's old Footprint big mortise chisel and slide it gently into the slot and prise off the back (not for the clumsy nor the faint-hearted). Yes, this tough, adventure's watch has a prise-off back!. However, the rest is pretty easy. Push down on a button thingy and the crown pulls out. More gentle prising on the plastic body gets the movement out, finally granting access to the hands :- as suspected, the hour hand was up too high and a bit loose.

FYI, here's the data in various places on the back of the movement:

1IMP = 0.33 S/MONTH
ETA E10.351 SWISS V8
BAT 399 θ9.5 H2.6 1.55V

I do love the 0.33 sec/month but the Aerospace really is functionally disadvantaged compared to the far-eastern competition. Having said that, it sits well on the wrist, looks good and has the name.

Best regards,


Thursday, March 12, 2009

Abe Lincoln's watch opened!

A gold watch owned by Abraham Lincoln bears a message marking the start of the U.S. Civil War, but the president never knew of the "secret" inscription uncovered on Tuesday at the National Museum of American History.

Click here for full story and a link to some pics.

Makes quite a change from just the watchmaker's initials or State license number!

Best regards,


Thursday, February 5, 2009

Breitling Aerospace - first impressions

Well it took a week to get here via U.S. parcel post for which I paid $20.00 a là classic eBay transaction with the over-priced shipping.

I put it straight to work . . . .
Aerospace on wrist in my shop

It's the SuperQuartz model no E75362, blue dial. I have to admit to not falling immediately in love with it, in spite of it's name and general reverence among our community.

Accurate, simple layout, titanium, medium size (40mm), clear golden LCD displays, bi-directional bezel, sapphire dial with AR coating both sides, excellent lume and, of course, the name.

Horrible numeral font, fiddly function selection (being a lefty, I have to remove the watch to do anything), low-volume tinny beep, no backlight, no chrono split-time, not that many functions. Can't even set the minutes and seconds different to basic digital time other than by fiddling around with the reset function and thereby messing up the 2nd timezone - duh.

Unfortunately, there's some stiff competition from another member of my collection . . .
Citizen Wingman

The Wingman has many more timezones and two alarms, not just one; it's hands can be set completely independently of the digital (LCD) time. It has a really loud alarm and a good backlight.

Best regards,