1330: The first mechanical clocks having a wheelwork emerged in the 13th century. They were often mounted in churches and monasteries. Richard of Wallingford (1292-1336), abbot and mathematician at the Abbey of St. Alban, built a very complex machine. It was a mechanical marvel and probably one of the most sophisticated clocks ever constructed. It showed three particular features that remain enigmatic to this day: the main 24-hour-wheel with a strike mechanism that drives everything else, a lunar eclipse mechanism, and a planetary gearing. As such, it could be used like a geared astrolabe. In his treatise "Tractatus Horologii Astronomici" (1327), Richard describes its operation. He worked on this clock more than ten years, but it was accomplished 20 years after his death by William of Walsham. It disappeared during the dissolution of the St. Albans Abbey in 1546.

Richard of Wallingford is also said to have constructed another device which he called "Albion". It was able to make astronomical enquiries due to the Ptolemaic system. It showed lunar and planetary orbits as well as eclipses. In 1965 copies of Richard's original notes were discovered in the Bodleian library at Oxford University. They were translated and interpreted by John North. Those plans found at Oxford were for construction of an undefined clock and not necessarily a complete description of the one which Richard constructed. On many features, the plans are not specific, so a considerable amount of conjecture and imagination were required. This lead to several attempts to re-model the clock. One replica was built by Eric Watson and is now in the Wallingford Museum. Another one was completed by a group of enthusiasts in 1988 and is located at the St. Albans Cathedral at the present time. One further is exhibited at the Museum of Time in Rockford, Illinois (Image). The invention of the clock was an important branch leading to the planetarium, for it is based on the comparison of periods. Thus, it is a kind of modelling of the planetary motions.