Dating english patent numbers
The patents journal contains details of new UK patent applications and changes to the register.
You can ignore the number at the right hand corner of the diamond - this tells us how many items were included in the registration, (sometimes known as bundles or packages).
Once you know the patent number, you can find out other information such as when the patent expires or who has a license to manufacture or distribute the invention.
During the period 1842-1883 the British Patent Office issued a diamond mark along with the registration number when a design was registered.
Some American watch brands did not use a consistent series of serial numbers, but most of the big manufacturers did.
Most vintage Swiss pocket watches did NOT have serial numbers and can't be dated by this method.
Search for dating english patent numbers:
Since your serial number falls between those two numbers, you know that your watch was made in 1917 or 1918. Cases and watches were often made by different companies and each usually has its own serial number. Be sure to use the table that is specific to YOUR brand of watch when looking up your serial number.