These numbers are stamped on the back (outside) of the case. If there is no two symbols, it could be that your watch was made before 1948. The code is very simple. L=50, M=60, N=70, P=80, T=90. The code was usually stamped on the back of the watch case. For exabple, If you have a Bulova watch with the stamp M3 then it was made in 1963. Information about the Star Watch Case Co. Can be found in the book, History of the American Watch Case, (see References, below). Starke and Fred Herman founded the company in Elgin, IL in 1897. The company moved to Ludington, MI in 1905, where they eventually employed about 150 people. Until WWI, only pocket watch cases were made. There are two numbers engraved on the caseback of your watch. One number is directly below the other. The bottom number is your serial number. It is generally comprised of two or three letters followed by four numbers. In 1979, Star was sold to Precision Watch Case Co., a subsidiary of the Swiss watch making conglomerate SSIH. Three years later, production was shut down and the company went out of business. In 1975, the last year, only 75 employees were left. The building fell into decay, and was demolished in the 1980's. A GENTLEMAN'S 9CT GOLD SWISS KEYLESS POCKET WATCH by the Omega Watch Company, the movement with 21 jewels and lever escapement, tested 5 positions, with white enamelled dial having arabic hour numerals and subsidiary seconds dial, having Omega trade device, the case, with gold inner plate, hallmarked Birmingham, 1924, A.L.D. (Dennison Watch Case Co Ltd).

• Star Watch Case Company Serial Numbers
• Star Watch Case Company Serial Numbers Lookup

Aaron Dennison was an important pioneer in watchmaking by machinery; in fact it could be said that he was the most important pioneer, in that it was his ideas that started the mass production of watch movement parts by machinery in America, which had major knock-on effects on watchmaking in Switzerland and England. After initiating a revolution in watchmaking, Dennison set up a company in Birmingham, England, to make watch cases, and many collectors will have watches with cases made by the Dennison watch case company.

Aaron Lufkin Dennison

Aaron Lufkin Dennison was born in the USA on 6 March 1812 in Freeport, Cumberland County, Maine, the son of Colonel Andrew Dennison and Lydia Lufkin. His father was a cobbler by trade, but Aaron didn't like shoemaking and had a mechanical turn of mind, so in 1830 he was apprenticed to James Carey, a clock and watch maker, gunsmith and gold and silversmith of Brunswick. In 1833 Dennison set up on his own as a watch repairer, but shortly after entered the employ of Jones, Low and Ball where he learnt from Tubal Hone, then considered to be one of the finest watchmakers in the country. In about 1840 he began to think about manufacturing complete watches in the United States by machine. In 1849 Dennison approached Edward Howard, partner in the company Howard & Davis, with his plan, and a factory was created at Roxbury, Massachusetts for the new firm which, after several initial changes of name, was called Dennison, Howard & Davis. The firm operated until the beginning of 1857 when it went bankrupt.

The assets of the bankrupt company were auctioned and the buildings and some machinery were bought Royal E. Robbins, who restarted watch manufacture under the name of Tracy Baker & Company with Dennison superintendent of the mechanical department. Robbins found Dennison to be rather too creative when graft and application was required, and in December 1861 he was dismissed. After Dennison had left, the new cheaper William Ellery model watch he had been trying to introduce became a financial success for the company, selling in large numbers to soldiers during the American civil war. From the rather confusing jumble of company restructurings that followed eventually emerged the American Watch Company of Waltham, Massachusetts, but Dennison was no longer involved in the company he had helped to found.

In 1864 Dennison and A. O. Bigelow set up the Tremont Watch Company in Boston with the idea of buying in the small fine parts, such as the balance, escapement and train wheels from Switzerland, where wages were lower than in America, and making in America the larger parts, such as the watch plates and mainspring barrel, and assemble watches. Dennison went to Zurich to supervise the ordering and delivery of parts to America.

The strategy was initially successful. In 1866 the company relocated to Melrose, Massachusetts, and was renamed the Melrose Watch Company. At the same time, Bigelow decided to make all the parts of the movements, and to increase production to 100 per week. Dennison disagreed with this and left the company. The new strategy was not a success and the Melrose Watch Company ran out of money and failed in 1868. Dennison returned to Boston and tried to form a new company to purchase the machinery and factory of the Melrose Watch Company, but failed. After much searching he found investors in Birmingham, England, who were prepared to put up the capital to buy the Melrose machinery and form a watchmaking company.

The company was initially called The Anglo-American Watch Company. The watches were understandably American in nature, with going barrels rather than fusees, and the initial products, uncased movements, were sent to America for sale, but there was little demand because of a financial recession at the time meaning that the market was already over supplied.

The name of the company was changed in February 1874 to The English Watch Company, presumably indicating a change in focus to selling watches on the British market. It appears that Dennison left the company at around this time.

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The Dennison Watch Case Company

In 1874 Dennison set up a watch case manufactory in the Handsworth area of Birmingham which eventually became the Dennison Watch Case Company. The early history of the company is rather unknown, despite the best efforts of Philip Priestley with the help of descendants of the founder to uncover it. A date of 1875 is suggested by a long service award to William McBeth in 1929 in recognition of 54 years service from the foundation of the company. However, it is generally believed that the business was started in 1874, coinciding with the establishment in Britain of a branch of the American Waltham Watch Company. Waltham began importing movements from its American factory and was desperate to find someone who could make the large numbers of cases required.

A record in the Birmingham Trade Directory of 1876 indicates a possibility that Edward Howard, one of the founders of the American company with Dennison and Davis in 1850, might have been an investor.

Alfred Wigley, an engraver, polisher and springer of watchcases, was involved in some way right from the start, eventually becoming a partner in 1879. The company was called Dennison, Wigley & Company from 1879 until 1905.

In August 1888 The Watchmaker, Jeweller and Silversmith reported that Dennison & Wigley were making watch cases so successfully as to be able to send quantities to America in spite of the import duty charged on them. The company employed at the time 100 hands and the factory was “lighted throughout with electric light”.

Later History

Aaron Dennison died on 9 January 1895 aged 82 and his son Franklin took over his role. In 1905 the company was incorporated and became the Dennison Watch Case Company Limited.

After many successful years the company ran into financial troubles in the 1950s. Major Gilbert Dennison, C.B.E., Chairman of the Board, died in April 1957 at a time when conditions were difficult because of Swiss and Japanese competition. Later that year there was a difference of opinion at board level that led to the resignation of Arthur G. Dennison, who set up the Dennison Gold Plate Co Ltd, at Kineton, Warwick. This subsequently became the Gold Plate Division of D Shackman & Sons Ltd, of Chesham, who had become serious competitors to Dennison.

The Dennison Watch Case Company Ltd. failed in February 1967 due to insolvency and the factory in Birmingham was closed. In April 1967 there was a two-day sale of the factory assets and some of the equipment was sold to Shackman & Sons, where it was used until the mid-1980s for the production of watchcases and bracelets.

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Dennison and Waltham

The American Watch Company at Waltham, Massachusetts, could produce more watch movements than they could sell in the USA, so in 1874 they began to export surplus movements to Britain. Although they had succeeded in mechanising the mass production of watch movements, advances in watch case making hadn't kept pace with increased production and cases were not in the same surplus. This meant that movements were exported bare or uncased and they then looked to English watch case makers to supply cases to house them.

At the time there were no English watch case makers who could supply the quantities of cases that were needed, so at first Swiss, and even some American, watch cases were also imported into Britain. In 1878 the Select Committee of the House of Commons looking into gold and silver hallmarking, took evidence from Alfred Bedford, at the time manager for the American Watch Co. of Waltham in the UK. Bedford stated that in 1877 Waltham UK had imported 5,000 watch cases from the United States and 18,000 from Switzerland.

The first major customer for Dennison watch cases was the American Watch Company of Waltham, and the coincidence of the date of 1874 in Aaron Dennison leaving The Anglo-American Watch Company and setting up a case making company, together with the opening in 1874 of the London office of the American Watch Company looks very significant. In fact, Waltham had a significant role in starting the business.

The London office of the American Watch Company at Waltham was first opened by Robbins & Appleton, but soon placed in the hands of N. P. Stratton who was directly responsible to the factory at Waltham. Stratton visited Dennison at Birmingham to ask if he would act as representative for the Company in England, but Dennison was not keen on the idea, probably feeling that a role as a travelling salesman was beneath him at his time in life, over 60 years old, and with his business experience. Dennison stated terms on which he would take the job, which Stratton sent to Royal E. Robbins for approval, but Robbins declined. Stratton then hired Dennison's son Edward instead. However, Robbins did not harbour any ill will against Dennison and gave substantial assistance to his final effort to establish a successful business of his own.

All the hallmarked gold and silver watch cases made by Dennison to house imported American Waltham movements had the sponsor's marks of either Frederick Francis Seeland, who was manager for the American Watch Co. of Waltham in the UK before leaving in late 1876 to take over at IWC, or the A.B of Alfred Bedford, who took over from Seeland as manager of Waltham UK.

When it began importing watch movements to Britain, Waltham had difficulty obtaining enough cases for them. They imported some American and Swiss cases and had them hallmarked at the Chester Assay Office. The first sponsor's mark for Waltham, F.F.S. in cameo, was entered at the London Assay Office on 2 November 1875 by Frederick Francis Seeland, Assistant Manager, Waltham UK. Two further FFS cameo punches followed on 17 December 1875 and February 1876.

In an attempt to make some sense of the dates I searched the records of the London, Chester and Birmingham assay offices for the names of people connected with Dennison. The results for the period up to August 1876 are tabled below. It is notable that the first Waltham mark is the F.F.S entered in November 1875. Two earlier marks were entered by Alfred Wigley, but it is not known exactly when he started work with Dennison.

What happened during the period between 1874 when the Waltham office was set up in London and the entry of the first sponsor's mark in November 1875 is not known. Waltham probably ordered cases from English case makers who marked them with their own sponsor's mark.

It is significant that neither Alfred Wigley's or Aaron Dennison's registered sponsor's marks appeared on the cases they made for Waltham. In evidence in 1887 to the Select Committee examining proposed changes to the Merchandise Marks Act, Alfred Bedford, the General Manager in Europe of the Waltham Watch Company, was asked 'Is there not a branch of the American watch manufacture established in Birmingham?' to which Bedford replied 'It is the case shop.'

In answers to other questions, Bedford stated 'At our case factory at Birmingham we turn out something like 50,000 cases a year for our watches.' (emphasis added) and 'We have at our factory at Birmingham received under permission from me orders to make 500 or 1,000 cases ....' (emphasis added). So it appears that Waltham had some interest in the company, and for Bedford to give permission for work to be done he must have had some authority.

The '500 or 1,000 cases' that Alfred Bedford mentioned in his evidence to the Select Committee were ordered from Switzerland. Bedford said they were to house Swiss watches and that they had been ordered specifically to obtain cases with English hallmarks. His sponsor's mark A.B had been struck on them. When watches with these cases and Swiss movements had started to come into the country he had made some efforts to find out where they , but he had never been able to trace them.

The annualised figures for 1876 and 1884 are calculated from figures for 11 and 5 months respectively.In evidence, Alfred Bedford said that a a Waltham watch in a silver case would sell at retail for about 50 shillings (£2.50). The Waltham sales figures represent the wholesale price and the retailers mark up is not known, but assuming that the retailer sold watches for twice the wholesale price, £50,000 in sales would represent about 40,000 watches, and £100,000 would be about 80,000. Some watches would be in gold cases, which would be considerably more expensive, so the numbers would actually be lower than this. In 1887 Bedford said that the case factory in Birmingham turned out about 50,000 cases a year. Given that the peak output of the whole of the English watch industry in the nineteenth century was about 200,000 a year, it is easy to see how the Waltham imports would have a big effect.

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A L Dennison and Early Waterproof Watches

There are stories that Aaron Dennison was involved in early waterproof watches and invented the screw down crown, but despite searching I have not found any evidence to support this and I believe that the story is apocryphal.

Dennison and the Screw Down Crown

Donald de Carle in Practical Watch Repairing, in the chapter on Water-Resistant Cases (on page 276 in my copy), says “There are three popular types of [water resistant] button and pendant. The screw button and pendant, originally invented by A. L Dennison as long ago as 1871, is used in various forms today ...”

I have seen another reference to this story in an excerpt from an American publication on the NAWCC web site as shown here. The NAWCC library have been unable to trace the publication in which this appears.

In The Principles of Waterproofing Watches Henry Fried says that Dennison encased watches in waterproof cases as far back as 1871, and that New York watch collector Louis Romaine has a Waltham watch with one of these cases. The problem with Fried's account is that he says that Romaine's watch has a screw cap, and he illustrates it with a figure from an American patent granted to Ezra Fitch. Fitch's patented design is different to a design patented by Dennison in 1872. In fact Romaine's Waltham watch was one of a number of similar watches with a case made in America to Fitch's patent. Dennison had absolutely nothing to do with it.

The use of a screw cap to enclose the crown and seal the gap where the stem enters the case is not really rocket science. It was used on “travellers'” or “explorers'” watches in the 1870s, such as those commissioned by the Royal Geographical Society. A cap over the crown was simple and effective, but not a very elegant solution to the problem. A much more effective solution was to use the crown itself as the cap, to arrange for the crown to screw down on the pendant or stem tube. A crown that screwed down onto the pendant was patented by Fitch in 1881, and this appears to have been the first true screw down crown.

The claim that Dennison invented the screw down crown is repeated in several places, so it might be thought that there may be some truth in it, but I have found no substantive evidence in its support. I have never seen a Dennison watch case from the nineteenth century with a screw cap over the crown or a screw down crown.

I think that this is just a tale that grew and changed in the telling and retelling, and that in fact Dennison did not invent the screw down crown.

Dennison's 1872 Patent

I asked the UK Intellectual Property Office in Cardiff to search for a Dennison patent of around 1871 and they came up with two; No. 356 dated 3rd February 1872 and No. 1113 dated 31st March 1874. These were the only two patents they could find attributed to Dennison around 1871.

• Patent No. 356 describes a watch with a case made air and water tight by screwed back and bezel, the winding arbor and push piece for engaging hand setting “work in packings so that they may work air and water tight.” The drawings accompanying the specification clearly show these packings, and there is no screw down crown there. This design would most likely have have been conceived in 1871 and I take it that this is the patent that de Carle, Fried, etc. are referring to. It is described in further detail below.

• Patent No. 1113 is for a Up and Down indicator on the dials, showing the state of wind of the main spring, and also a means of letting down a main spring.

On 3rd February 1872 Aaron Dennison of Handsworth, in the County of Stafford, Watch Manufacturer, deposited an application and preliminary specification for a patent for Improvements in Watches and Pocket Chronometers, which were said to consist of constructing the parts of watches and chronometers so that they are simplified and perfected, and the cases made air and water tight. On 29th July 1872 this application was approved and Dennison was granted British patent No. 356.

To make the case air and water tight, in place of the normal hinged bezel, Dennison designed a bezel with an external screw thread which screwed into a thread in the opening at the front of the case, from inside the case. I have circled this in red on the left hand side of the picture. The bezel is item 'b' with external screw thread 'd'. The bezel screws from inside the case into the thread in the front part of the case, part 'e' in the diagram.

The back of the case 'f' had an internal thread which screwed down onto a thread 'g' formed on the middle part of the case. The small screw labelled g² was there purely to give some grip for screwing and unscrewing the back. This must have been before Dennison conceived of using the peripheral 'coin edge' milling seen on later Dennison screw cases, which is not surprising, the patent was written several years before he started his watch case factory.

The winding stem and push piece for engaging the hand setting mechanism were provided with packings of an unspecified nature to make them 'air and water tight.' Note that these were simple gland packings, there was no screw cap or crown mentioned and I am sure that the story that Dennison invented the screw down crown is wrong.

This case was designed before Dennison set up his watch case works, but shows that he was thinking about watch cases as well as watch movements. The patent also covered a mechanism for winding and setting the watch via the crown, using a push piece to put the keyless mechanism into the hand setting position. Winding and setting the hands was an important consideration for a sealed case, because it was common at the time for the case to be opened to perform these operations, but there is no suggestion that Dennison invented keyless winding and setting.

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Dennison Sponsor's Marks

Watch cases made by Dennison which were not made for Waltham are usually easy to identify as they are stamped 'Dennison Watch Case Co.'. Gold and silver watch cases were also stamped with Dennison's registered sponsor's mark ALD or A·L·D in order to be sent for hallmarking - the assay offices required the sponsor's mark to be composed of the two or three initials of the 'responsible person' at the company, a company name or trade mark was not acceptable.

Dennison's sponsor's mark A.L.D in cameo was first entered at the Birmingham Assay Office on 20 April 1876, the address given as 24 Villa Road, Handsworth, Birmingham. Between 13 September 1879 and 30 March 1905 five similar A.L.D marks were entered for Dennison, Wigley & Company. From 16 November 1906 marks were entered in the name od the Dennison Watch Case Company Limited.

The picture to the left shows a silver case marked with both the Dennison Watch Case Co. and Dennison's A·L·D sponsor's mark. It has the anchor town mark which the Birmingham Assay Office stamped on native (i.e. not imported) items, the lion passant, the walking lion, indicating the fineness of the silver as sterling, and the date letter 'q' for the Birmingham Assay Office hallmarking year of 1915 to 1916.

Dennison made two grades of gold and silver watch cases, standard and special; the special indicating that the case was made from thinner sheet material.

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Base Metal and Plated Cases

Dennison also made gold plated watch cases. Gold-filled or rolled gold plate is a composite material where sheets of gold are bonded by heat and pressure to a core of base metal such as nickel or brass. The thickness of the gold determines how long the item will last in normal use before the gold wears through and the base metal shows. Gold filled should be thicker and constitute at least 1/20th of the weight of the metal in the entire article, rolled gold plate must constitute at least 1/40th of the weight of the metal in the entire article. The layer of gold in gold filled or rolled gold plate items is much thicker than electroplated gold, and therefore longer wearing. Because this material is not solid gold it cannot be hallmarked.

Initially an explanation of the process was engraved inside of Dennison cases, together with the expected lifetime of the gold plate in years, which was the length of time under normal wear that the gold covering was expected to last before it wore through and the base metal showed. On later cases this information was indicated only by one of three words:

• Sun with inside and outside layers of 14 carat gold, guaranteed for to wear for 25 years.
• Moon with inside and outside layers of 10 carat gold, guaranteed to wear for 20 years.
• Star the layer on the outside of the case 9 carat gold, guaranteed to wear for 10 years. The inside of the Star case, which of course was subject to less wear, was electroplated with a thin layer of gold for further economy.

Dennison gold filled watch cases are very good quality and are often found in nearly new condition today. If the gold plate has not worn through, then the case looks just like a gold case, because of course you only see the surface which is gold, but the prices are much more reasonable than for a solid gold case. Why would someone pay more for a solid gold case when you can't see the difference? A solid gold, hallmarked, watch case is a valuable thing, a store of wealth.

Sun, Moon and Star Trademark

A mark consisting of three symbols, a radiant sun, crescent moon and a star, was stamped on many Dennison cases, including cases made of nickel. This mark does not appear to indicate any specific type or grade of material but was simply a trademark. A similar mark with no sun but two stars was registered on 16 October 1920 by the Dennison Watch Case Company as a trademark.

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Star Watch Case Company Serial Numbers

Negative Setting

Many of the watchcases made by Dennison until the 1950s were for negative set movements. Negative setting is usually associated with American movements to the extent that it is sometimes referred to as American setting, because it made it easy to marry up the customer's choice of movement and case in the shop. But there are also watches with Swiss negative set movements in Dennison cases.

A negative set movement requires the provision of a detent sleeve spring in the pendant of the case. The image of the Dennison Patent Safety Bow shows a detent sleeve in grey below an externally threaded brass nut that is used to adjust the position of the sleeve in the pendant.

A watch with a negative set movement can be distinguished from one with the usual method of setting by the absence of a setting lever screw. This is illustrated in the discussion about a Tavannes patent.

These detent sleeves tend to break, which was not an undue problem when Dennison's were in business. But when the factory closed down, such sleeves were discarded by the dustbin load and today are hard to find.

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Screw Cases

During the Great War, the War Department issued wristwatches such as the one shown here to “other ranks” such as signallers who would not be expected to purchase their own wristwatches. The 'pheon' or broad arrow on the case back denotes it as War Department property. The watch has a screw back and bezel case made from nickel, and the movement was made by the Swiss ébauche manufacturer A Schild. You can see a picture of the movement on my Movements page.

The substantial “screw back and bezel” case of this watch is made of nickel, so it carries no hallmarks or sponsor's mark to show who made it, but the case has several very distinctive features; the milling that gives a grip when unscrewing the back and bezel, the flattened pumpkin shape of the crown, and the large diameter stem tube that is cut away at the back and front to allow the bezel and back to screw down.

The pictures here of another of these watches shows another of these wristwatches with War Department markings in a silver case. The manufacturers marks and hallmarks those show that this case was made by the Dennison watch case company of Birmingham and hallmarked in Birmingham. The assayer's mark (date letter) 't' shows that the case was hallmarked in the Birmingham hallmarking year 1918 to 1919.

The silver case is clearly from the same manufacturer as the nickel case discussed above. The milling that gives a grip when unscrewing the back and bezel and the large diameter stem tube cut away at the back and front to allow the bezel and back to screw down are the same. The large onion crown is a recent replacement for the original flattened pumpkin crown which was missing when the watch was found. The inside of the back of the silver case is clearly marked with Dennison's trademark and sponsor's mark, and there can be no doubt that both cases were made by Dennison in Birmingham.

These Dennison screw wristwatch cases usually have a very thick mineral glass crystal rather than the unbreakable crystals that were fitted from 1916 onwards to Swiss wristwatches aimed at service men. This suggests that either someone in the British War Department wasn't happy with unbreakable crystals for some reason that isn't immediately apparent, or that the supply of these crystals was restricted to Swiss watch case manufacturers and not exported.

The same cases in silver with Dennison marks are seen quite frequently without the military broad arrow, but silver cases with the broad arrow are uncommon. A nickel case was perfectly serviceable for military use, and was rustproof, so the extra cost of a silver case was not justified by military requirements. Most officers watches purchased with their kit allowance were silver, but these did not carry the pheon of War Department property.

The advert here appeared in an April 1915 edition of Land & Water magazine and showed that Dennison were making these screw cases from at least 1915. The case in the advert has a screw back and bezel case with the same milling on the bezel as the issued wristwatches, but the crown is next to the case and there isn't the large diameter pendant or stem tube of the issued cases. The case in the advert is for a movement that is normally set; the cases with the large diameter stem tube are negative (American) set set and the tube is required to accommodate the detent mechanism.

The advert proclaims that this Dennison case is “the Original Screw Case”. There is no further detail to back up this claim, but it refers to a Dennison patent of 1872 for a case with a screw back and bezel, although the bezel was screwed into the middle part of the case from inside, not outside as in the watches here.

The advert also states that 'Whatever watch you choose can be supplied in a 'Dennison Quality' case.' This is rather puzzling because almost all wristwatches in Britain at the time were Swiss imports and most came into the country complete with case - it seems to imply that people would get the case of a Swiss wristwatch changed by a jeweller, which is unlikely.

An alternative explanation is suggested by the fact that these Dennison adverts often appear in the magazine next to an advert for Waltham wristwatches. There was a very close relationship between Dennison and the UK branch of the American Watch Co. of Waltham. In fact, the Dennison watch case factory was originally set up in the 1880s in close conjunction with the American Watch Company of Waltham to manufacture cases for Waltham movements imported from the US. It was common in America for watch movements and cases to be made to standard sizes, and a retail customer could then choose which combination of movement and case he desired, which would be fitted together by the shop keeper at the point of sale. It may be therefore that the Dennison advert meant you can have any Waltham watch movement you choose in a Dennison case.

These Dennison screw cases were not used only for Waltham movements, they are also seen with Swiss movements, often Tavannes / Cyma, who were the manufacturers of the movement in the silver case. Presumably these movements were imported from Switzerland bare or uncased, and may have been cased at the Dennison factory in Birmingham.

The Waltham movements that these screw cases were originally designed to accommodate movements had typical American negative set keyless mechanism. Swiss movements fitted to these cases are also usually (always?) also seen with negative set keyless mechanism.

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Stainless Steel Cases

Stainless steel began to be used for watch cases in Switzerland in the early 1930s, partly because it was cheaper than gold or silver which was an important consideration during the Great Depression, and partly because it was a new “wonder material”; more attractive and more durable than nickel or ordinary steel.

The Dennison Watch Case Co. Ltd. registered “Denisteel” as a trademark for stainless steel watch cases on 17 April 1934.

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Patents

In addition to Aaron Dennison's 1872 patent for a waterproof watch discussed above, over the years of its existence the Dennison Watchcase Company was granted many patents for aspects of watch cases. They are not all listed here, but I have itemised a few that have caught my attention.

GB25045 Safety Bow

An application for a patent for “Improvements relating to Watches or Watch Cases for use in connection with Bracelets or Wristlets” was lodged by Gilbert Dennison on 10 November 1911, and British patent 25045 was granted on 11 November 1912.

The subject of the patent was a means of attaching wire lugs to the cases of open face watches to take a strap so that they could be worn as wristwatches. The problem addressed was that an open face watch has the crown at 12. In the patented design the upper lug was made large enough that it went above and around the crown. The ends of the wire loops were attached by ball joints to a block of metal soldered to case. The upper lug was made large enough to straddle the crown, and the ball joint allowed it to be swung out of the way for winding. This was not rocket science and a patent was not really justified, on the grounds that the idea would be “obvious to a person skilled in the art.”

However, the attachment on the lugs to the case was later referred to as the “Dennison Patent Safety Bow”, even though this idea is not mentioned in the patent. When watches were key wound, the bow was attached to the pendant by a screw passing through the pendant. The introduction of keyless stem winding meant that this was no longer possible due to the stem running inside the pendant. Various methods of attaching the bow were developed, from a simple snap fastening which was not very secure to separate screws for each side of the bow, which was fiddly to make. The Dennison safety bow was nearly as simple as a snap fastening but more secure.

The image here from a later patent, GB1390, is a cross section showing how the patent safety bow was attached to the pendant. The ends of the bow were provided with balls which were assembled into sockets on the pendant, which were subsequently burnished over, “thus avoiding all risk of being detached.”

Although the patent didn't actually mention watch bows at all, which are a feature of pocket watches, an article in the Horological Journal say that the Dennison Safety watch bow was “generally introduced” in 1912, confirming that this was the patent that Dennison claimed to protect the design.

GB1390 Waterproof Crown

In 1915 Gilbert Dennison was granted British patent Mo. 1390 for a waterproof screw down crown.

There were some minor differences between this design and a US patent granted to Ezra Fitch in 1881, but not very great. The design also had all of the deficiencies of Fitch's design. It used the winding ratchet to enable the crown to be screwed down after the mainspring was full wound, which required a left hand thread on the outside of the pendant that was exposed to dust and dirt, and it lacked a clutch that would have allowed the crown to be unscrewed with the watch fully wound. All in all it was not a great invention.

It is not known whether any watches were ever made with Dennison's screw down crown. Philip Priestley records that in 1913 Gilbert Dennison collaborated with Mr M L Bateman in the design and development of waterproof watches for the 'fateful Scott Antarctic expedition of 1914/16'. However, Scott's last expedition started in 1910 and he died on the ice shelf at the end of March 1912. Scott's watches from this expedition are well known. One was an alarm watch that he used to remind himself to take regular activity to avoid frostbite, this watch is in the BHI collection at Upton Hall. The other watch was a waterproof explorers' watch supplied by S. Smith & Sons that is in the collection of the National Maritime Museum at Greenwich. I have not been able to discover details of any other waterproof watches that were used on that expedition, but as Scott's expedition was over before 1913 this story seems unlikely.

Philip also says that in 1914 Dennison produced a special water resistant case for the 1914 Shackleton expedition to Antarctica and shows a photograph of the watch, supplied by John Purser & Sons Ltd. of Cardiff. This watch has a bulky crown which might be of the Dennison patent design.

GB269722 Cachecase

A British patent was granted on 28 April 1927 to the Dennison Watch Case Company and Charles William Burrows for a “push together” (my term) watch case. The bezel and middle part of the case are made in one piece, forming the front or top part of the case. The case back has an upstanding flange which pushes up into the front part of the case and is held in place by friction. The strap lugs were attached to the top part of the case so that when the watch was worn the bottom part was trapped between the wrist and the upper part so that there was no possibility of its coming out. This design of case was called “Cachecase” by Dennison.

GB419642 Dust Proof Crown

A British patent was granted on 13 November 1934 to the Dennison Watch Case Company and Gilbert Dennison for a dust-proof crown. The crown has an internal spring loaded sleeve which takes the place of a pendant or stem tube on the case, sealing the gap between the case and the stem against the entry of dust and “other foreign matter.”

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Dennison Sovereign Cases

The gold Sovereign coin was first introduced in 1489 on the orders of King Henry VII. Gold Sovereigns were struck throughout the reigns of succeeding Tudor monarchs until minting ceased early in the reign of James I. Issue of Sovereigns by the British Royal Mint recommenced in 1817 after the end of the Napoleonic Wars. Gold Sovereigns were also made from 1850 in Australia, and later in Canada, South Africa and India. Gold coins in general were withdrawn from circulation in Britain on the outbreak of the Great War in 1914. Sovereigns did not return to circulation in Britain after the war, but they remain legal tender and are still made today.

Dennison Sovereign cases were made with either single or double tubes, side by side, for holding holding the coins. Philip Priestley's book on Dennison (Ref. 1, p.87) records only that Dennison Sovereign cases were made between the wars in solid gold and silver, but it is known that they were also made in rolled or plated gold and silver, and in nickel. A correspondent Peter sent me an image of a case with Dennison's sun, moon and star trademark in the lid and an inscription around bottom piece “English Make Guaranteed Solid Nickel”.

A correspondent Ewen B. contributed the images here of a 9 carat gold Dennison Sovereign case. It is a single tube version. The coins go under the horse-shoe shaped retainer, pushing down the plate underneath which is spring loaded. The case can be dated 1913 to 1914 by the Birmingham Assay Office hallmark. Date letter punches were changed when new wardens were elected, which at the Birmingham Assay Office was at the end of June, so the same date letter was used over two calendar years. At the Birmingham Assay Office this was from 1 July of one year to 30 June the next year.

The date letter is the Birmingham Assay Office “o” of 1913 to 1914 but the surround (shield) is a different shape to that listed in most references including Jackson's. It may be that the Birmingham Assay Office used different surrounds for date letter punches of whatever size on all gold items, or that the surround was simplified for punches used only on smaller items. Whatever the reason, this illustrates the problem with most tables of hallmark date letters, which show only the punch marks used on large silver items and the first year in which the punch was used. The date letter punches used on small items and gold items are often different, and date letters were used over two calendar years.

Dates of Manufacture

Philip Priestley does not say over what period these Sovereign cases were made by Dennison, only that they were made “between the wars”. Since there were no British Sovereigns in circulation to be put into them at that time, it seems likely that case made between the wars would all have been exported to Commonwealth countries where Sovereigns remained in circulation. Australia, Canada, South Africa and India continued to use Sovereigns as regular currency after they had been withdrawn in the UK. Rather strangely, I have not seen a gold or silver Dennison Sovereign case with hallmarks dating to any later than 1913/1914, before the first world war, which seems to contradict Philips's assertion that they were made between the wars.

A correspondent Steve J. reported a 9 carat gold Dennison Sovereign case dated 1910 to 1911 by a Birmingham Assay Office hallmark, which was the first I had seen that showed that they were also made before the Great War.

The earliest positively dated Dennison Sovereign case that I have seen is the silver one shown in the image here, which was sold on eBay. It in sterling silver and has nice clear Birmingham Assay Office hallmarks for 1903 to 1904.

The auctioneers Bonhams sold a silver Dennison Sovereign case hallmarked Birmingham 1910/1911. Other ones have been seen dated by hallmarks to 1912/1913, 1915/1916. A quick survey of hallmarked cases sold on eBay recently showed many with cases dated between 1903 and 1914.

Many Dennison Sovereign cases that have been reported to me or listed at auctions are either gold filled, such as a single tube version in 14 carat rolled gold plate guaranteed to wear for 20 years, gold or silver plated, or nickel. They usually have Dennison's sun, moon and star trademark in the lid. These are not precious metal so cannot be hallmarked, which also means they cannot be accurately dated from a hallmark date letter.

The earliest definitively dated one that I have seen is the sterling silver 1903 / 1904 example. If you have an earlier hallmarked example, or one hallmarked later than 1914, please let me know.

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Dennison Powder Compacts

Philip Priestley's book on Dennison (Ref. 1, pp.89-90) contains descriptions of Dennison made powder compacts. Unfortunately no production dates are given. If you have one of these and it is hallmarked, please get in touch with details.

There were three models, the 200 was for loose powder with puff and mirror, the 150 and 350 models had proprietary inserts of powder, also with a puff and mirror. All models came in either 10 year rolled gold or sterling silver, the 150 and 350 also came in 9 carat gold.

The lids were made in a wide range of engine of engine turned finishes, or with enamel pictures of animals on sterling silver. Five enamels are illustrated in the book, a wild duck in flight, an Irish terrier in profile, and heads of an Alsatian dog, a fox terrier and a fox.

References

1. Priestley, Philip T: 'Aaron Lufkin Dennison, an industrial pioneer and his legacy', NAWCC, 2010.

If you have any questions or comments, please don't hesitate to to get in touch via my Contact Me page.

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