Complex sentence: The first machine was built by a Parisian clockmaker named Devrine, it took him a year to build it because, in order to make it work, he had to modify the patented design quite substantially.
Split into simpler sentences: The first machine was built by a Parisian clockmaker named Devrine, it took him a year to build it. But, in order to make it work, he had to modify the patented design quite substantially.