Notes:
Patented by Hope-Jones in 1907/8, the Synchronome was developed to become one of the most successful master clocks. It is popular with collectors, possibly because the slave dial, which is usually mounted in the top of the case, does not obscure the view of the mechanism.As a dating guide, the main framework was smooth enamelled until about 1930 and there was no damper on the gravity arm. After this date a crackle finish was introduced and a damper was fitted. The serial number is on the advance retard plate at the left side of the movement.
Clocks without a serial number are not as valuable as they were probably made from castings sold by the company to model engineers etc during the 1930s and early 40s. These clocks were also made by another factory (I have lost the reference..Coventry, I believe. Please help) and then have a serial starting with the letter "C".
There was a third "experimental" movement introduced in 1922 but only about a hundred were made as it was difficult to maintain.