Before the arrival of mechanical clocks in England, sundials were the principal means of telling the time. Even after domestic clocks became established during the late sixteenth and early seventeenth centuries, sundials continued to play an essential role because the earliest clocks were seldom sufficiently accurate to keep reliable time for long periods. As a result, they were regularly reset by reference to a sundial.

 

Many lantern clockmakers are believed to have supplied their clocks with a small brass sundial, often referred to today as a ‘windowsill’ sundial. These were made either by the clockmaker himself, by a scientific instrument maker, or, for wealthier customers, by one of London’s highly skilled mathematical instrument makers.

 

Today these small brass sundials are fascinating historical objects in their own right and provide an important link between the history of timekeeping and the development of the earliest domestic clocks.