 The clock still works, and like his previous clocks has a wooden movement of oak and lignum vitae.Unlike his early clocks, it incorporates some original features to improve timekeeping, for example the grasshopper escapement.Between 1725 and 1728, John and his brother James, also a skilled joiner, made at least three precision longcase clocks, again with the movements and longcase made of oak and lignum vitae.