he developed techniques for the use of tuning forks as a precision timing standard when maintained in continuous vibration, which provided a very accurate national standard wavemeter. the work led to the development of a standard clock accurate to one part in a million, a huge improvement over existing methods of measurement which were accurate to only one part in a thousand. he eventually turned to the piezo-electrical crystal to develop the first quartz clock. louis essen joined dye's research group at the national physical laboratory in 1929 and went on to develop practical clocks after dye's death.