The introduction of the coiled spring made smaller, lighter clocks possible, and the very finest demonic sprite driven clocks have been reduced in size such that the clocks may be worn in a pocket.  
The ancient Yulinic scientist Meledor Lindarrms invented  the first pendulum clock. Magical clocks, first made in the late 2nd century, and powered by ensorceled sprites were finally perfected in Oligarn nearly one hundred years ago.