Grasshopper escapement As a result, on the 18th of April 2015, the Guinness World Records organisation presented a World Record certificate to Martin Burgess for having made the most accurate purely mechanical clock working in free air. The clock remains at the ROG; in 2017 it was moved to the gallery containing the Harrison marine timekeepers where its performance continues to be monitored. Grasshopper escapement The grasshopper escapement is a low-friction escapement for pendulum clocks invented by British clockmaker John Harrison around 1722. An escapement, part of every mechanical clock, is the mechanism that gives the clock's pendulum periodic pushes to keep
Escapement is made from a special steel alloy with 36% nickel called Invar whose length changes very little with temperature, swings as free of external influence as possible sealed in a vacuum chamber and does no work. It is in mechanical contact with its escapement for only a fraction of a second every 30 seconds. A secondary "slave" pendulum turns a ratchet, which triggers an electromagnet slightly less than every thirty seconds. This electromagnet releases a gravity lever onto the escapement above the master pendulum. A fraction of a second later (but exactly every 30 seconds), the motion of the master