Although Graham succeeded to Tompion's business and continued his system of numbering, there are occasional unnumbered examples, the present clock included. In order to increase their output both Tompion and Graham worked through a system of journeymen, and the present clock, though fully of the standard associated with Graham, may have been produced towards the end of his life, as the arched style of the case would suggest. His most trusted and quite brilliant apprentice and later assistant was Thomas Mudge who succeeded Graham on the latter's death in 1751. The ingenuity and style of the alarm system is very indicative of Mudge's early work