



Contents The jewelling of movements is one of the aspects of watches that is least understood by novices. Simply put, the jewels are mostly low-friction bearing surfaces and they have little monetary value beyond the cost of labor to shape and mount them. Their use is excellently illustrated in a 1902 Illinois ad

What Are Pocket Watch Jewels and Why Use Them?



The jewels are very hard and resist scratching and wear. On a ten point scale, diamond is a 10. Rubies and sapphires are made of aluminum oxide and are a 9 in hardness. The only differences are trace materials that change the color.



Without a jewel you have a steel pivot in a brass hole. Brass is soft and wears easily. Furthermore grit imbeds into the soft brass and then acts like sandpaper and wears the steel pivot. Soon the brass hole is worn egg shape and off center allowing the pivot to go off axis. Similarly the steel pivot has grooves warn in it allowing a place for more grit to collect. I have seen pivots warn more than half way through. Now you have to drill out the old hole back where it is supposed to be and rebush it. The warn pivot has to be repolished or worse removed and replace with a new pivot. This is why a neglected low jewel watch can be more expensive to overhaul than an expensive high jewel watch.



The jewel experiences very little wear because it is so hard, unless the watch has been run for a very long time without cleaning. Dirt and grit cannot imbed into the jewel, causing less wear on the steel pivot.



Finally, (a) polished steel pivot on a polished jewel is a low friction interaction, which will allow more power to get to the escape wheel. This gives the escape wheel more action (larger swing) for better time keeping and less positional error.

Don Dahlberg, NAWCC Pocket Watch Message Board, 29-Apr-06 Click to expand... The jewels in a watch were, for the most part, the bearings. These were industrial jewels, not at all gem quality. They provided hard, low-friction, wear-resistant surfaces.

The Basic 7 Watch Jewels





1 Roller Jewel

2 Balance Hole Jewels

2 Balance Cap Jewels

2 Entrance and Exit Pallet Jewels



These are all involved in the controlled release of mainspring power to the train and thus directly affect the timekeeping rate of the watch. The basic number of jewels in an American “ Basic Jeweled Watch ” is 7, all of which are on the balance and escapement. The roller jewel, mounted on the balance assembly, is the reason for the odd number of jewels. All of the other jewels, up to 7 are added in pairs.1 Roller Jewel2 Balance Hole Jewels2 Balance Cap Jewels2 Entrance and Exit Pallet JewelsThese are all involved in the controlled release of mainspring power to the train and thus directly affect the timekeeping rate of the watch.

Additions Up To 15 Watch Jewels





From the 1860’s through the 1880’s, watches were said to be “ After the first 7 jewels in the balance and escapement, jewels were usually added in pairs, up to 15 jewels. Occasionally, some watch companies offered 13-jewel watches, putting the 3rd and 4th wheel hole jewels in the top plate, where they'd be visible to the customer, and not jewelling the corresponding holes in the lower (pillar) plate.From the 1860’s through the 1880’s, watches were said to be “ Full Jeweled ” or "Fully Jeweled" if they contained 15 jewels.

Does the Watch Have 13 or 15 Jewels?

When all of the holes in the top plate are jeweled, how does one know if the watch is a fully-jeweled, (15-jewel) watch, or a 13-jewel watch (which lacks the lower 3rd and 4th wheel jewels)? A number of watch companies made 13-jewel watches specifically to have the appearance of a fully-jeweled watch. However, since the object was to give the appearance without the cost, a less expensive method of mounting the jewels was used instead of using screw-down jewel settings. Thus, as a rule of thumb (there may be some exceptions), if the top plate holes are jeweled without screw-down jewel settings then the watch is probably a 13-jewel watch. If the top plate holes are jeweled with screw-down jewel settings then the watch is probably a 15-jewel watch.

Beyond 15 Jewels





Still, that 17th jewel generally isn't considered necessary and many high grade European watch makers didn't bother with it. It's not only the high grade European watches that don't have the unnecessary (well, very much less necessary) lower center jewel. In 1895, the best 18-size Elgin watch was the grade Nos. 149 & 150 (hunting-case and open-face),



Adding additional jewels (beyond 17), up to 19, usually produced a demonstrable improvement in timekeeping accuracy. In adding 2 more jewels to bring a watch up to 21, the increase in accuracy was more theoretical than practical. Any number of jewels over 21 usually failed to gain any additional timekeeping improvement. It should be noted that additional labor to properly adjust a watch did more to improve accuracy than adding jewels above 16 or 19. In fact, the Elgin grade In fact, a Canadian railroad watch inspector told me in correspondence that the Waltham people believed that the 19-jewel Riverside was their "best running" railroad watch, and the Canadian Ball Watch Company people said that the 16-size, 19-jewel Ball watch, which was based on the Waltham 19-jewel Riverside, was their best running watch! '



On page 19 of a July 1905 Webb C. Ball Watch Company catalog, the following is stated:

" 17 jewels equip a good railroad watch when properly finished and adjusted; 19 can be used by setting the two extra jewels in the barrel bearing; beyond that suggestions about additional jewels smack of brimstone and deceit. "



For a good online reference regarding jewel types and descriptions, Robert Sweet has posted an Moving upward from 15, jewels were added in pairs with the one exception being the upper center jewel in 16-jewel watches. The top center hole of a watch is subject to a relatively large amount of force. Poorly maintained watches of 15-jewels, or less, tend to exhibit wear in this hole. Thus, adding an upper center jewel reduces the friction and resultant wear associated with the higher forces. However, the lower center hole is relatively free of force, and hence, doesn't require a jewel. Thus, in the late 1880s, an upper center jewel began to be added, appearing in such watches as the 16-jewel, Columbus Railway King grade (and other Columbus grades). By the early 1890s, Illinois' 18-size, 16-jewel Bunn (having no lower center jewel) was the highest grade watch in their line. It was right at that time that Dueber-Hampden created and heavily promoted a new line of 17-jewel watches (having added a lower center jewel), initiating a market to shift to 17-jewel and higher jeweled watches over the next five years.Still, that 17th jewel generally isn't considered necessary and many high grade European watch makers didn't bother with it. It's not only the high grade European watches that don't have the unnecessary (well, very much less necessary) lower center jewel. In 1895, the best 18-size Elgin watch was the grade Nos. 149 & 150 (hunting-case and open-face), 20-Jewel movement having an upper center jewel but not a lower one. However, market pressure forced Elgin to increase their jewelling to 21-jewel by adding a lower center jewel within a few years.Adding additional jewels (beyond 17), up to 19, usually produced a demonstrable improvement in timekeeping accuracy. In adding 2 more jewels to bring a watch up to 21, the increase in accuracy was more theoretical than practical. Any number of jewels over 21 usually failed to gain any additional timekeeping improvement. It should be noted that additional labor to properly adjust a watch did more to improve accuracy than adding jewels above 16 or 19. In fact, the Elgin grade No. 240 B.W. Raymond , a 19-jewel, 18-size, Veritas model (three-quarter plate) movement, is considered by quite a few people to be one of the best timekeepers ever made. Similarly, Larry Treiman stated, in a June 10, 2012 Message Board thread: 'On page 19 of a July 1905 Webb C. Ball Watch Company catalog, the following is stated:For a good online reference regarding jewel types and descriptions, Robert Sweet has posted an Excerpt from Technical Manual 9-1575 , (War Dept. Tech. Manual), 6 April 1945.

Does A Watch Have 15, 16 or 17 Jewels?

full jeweled watch" (has at least 15 jewels) is to see if the top plate pivot holes are jeweled with screw-down jewel settings. If there are screw-down jewel settings, it is probably a 15-jewel movement. If not, and the jewels are friction-fit into the plates, then the movement has 11 jewels (or perhaps 13). This rule-of-thumb isn't infallible - there are exceptions, but it will hold up in most instances.



A quick check to see if an American-made watch has more than 15 jewels is to check to see if there is a



To determine if an American-made watch has more than 16-jewels there is another good rule-of-thumb that applies to watches built after 1890:

If it isn't marked as having more than 16 jewels, then it probably doesn't.

Like all rules-of-thumb, there are exceptions, but this applies in most cases. And, for those watches built prior to 1891 (when Dueber-Hampden launched an advertising blitz for its In viewing an American-built, 18-size, full-plate movement, a good rule-of-thumb to determine if it probably is a "" (has at least 15 jewels) is to see if the top plate pivot holes are jeweled with screw-down jewel settings. If there are screw-down jewel settings, it is probably a 15-jewel movement. If not, and the jewels are friction-fit into the plates, then the movement has 11 jewels (or perhaps 13). This rule-of-thumb isn't infallible - there are exceptions, but it will hold up in most instances.A quick check to see if an American-made watch has more than 15 jewels is to check to see if there is a center jewel in the upper plate or bridge. Almost all American-made 15-jewel watches (and lower, an exception doesn't come readily to mind) lack this center jewel. However, the presence of the center jewel doesn't mean that the watch has 17-jewels. A significant number of American-made 16-jewel watches of the 1889-1894 era (plus or minus a few years) were fitted with an upper center jewel, but not a lower center jewel. For example, in the late 1880s, there were a number of 16-jewel watches in the Columbus line and by the early 1890s, Illinois' 18-size, 16-jewel Bunn (having no lower center jewel) was the highest grade watch in their line.To determine if an American-made watch has more than 16-jewels there is another good rule-of-thumb that applies to watches built after 1890:Like all rules-of-thumb, there are exceptions, but this applies in most cases. And, for those watches built prior to 1891 (when Dueber-Hampden launched an advertising blitz for its line of 17-jewel watches ), only a very small percentage (less than 1%) had 17 jewels or more. On an earlier version of this message board, Tom McIntyre (a person whose opinions are highly regarded) agreed with an estimate of 10,000 of such watches built prior to 1891, a time by which the American jeweled watch industry had produced millions of watches.

References