Complex sentence: To make a striking clock that told Japanese time, clockmakers resorted to a system that ran two different balances, one slow and one fast; the appropriate escapement was swapped in and out automatically as the time moved from day to night.
Split into simpler sentences: To make a striking clock that told Japanese time, clockmakers used a system that ran two balances, one slow and one fast. The appropriate escapement was changed automatically as the time moved from day to night.