In the first half of 18th century the top English clockmakers were renowned for producing the best precision timekeepers in the world. Perhaps the most famous was George Graham (1673-1751), successor to Thomas Tompion and inventor of the cylinder escapement, the gridiron pendulum and mentor to John 'Longitude' Harrison. Graham supplied two best quality regulators to the Vienna Royal Court between 1740 and 1750. In 1745 the Viennese Astronomer Royal J. J. Marinonius published De Astronomica specula domestica et organico aapparatu astronomico, a detailed account of the inventory of the technical apparatus in use at the Imperial observatory in Vienna. Within this account is a published account of a month-going regulator by George Graham. The account included detailed drawings of the movement layout, wheel train, escapement and pendulum.
The movement of the present Viennese mean-solar regulator by Lazarus is remarkably similar in detail and concept to a typical Graham regulator. Similarities include the train layout, shape of pillar, shape and thickness of the brass plates, the 'Graham' dead beat, the bolt-and-shutter, the stop work and even the pendulum bob. Given the remarkable likeness it seems more than likely that Lazarus not only visited the Vienna Observatory but also held a Graham movement in his hands and copied its specification.
The fact that Lazarus made his clock some 55 years after Graham's death is a tribute to the latter's genius. But Lazarus was a a Gross Uhrmacher Meister and could not resist adding his own 'modern' technology including equation work with epicycloidal gearing and dual calendar.