isochronism

The discovery by Galileo of the isochronism of the pendulum, followed by Huyghens’s adaptation of that principle to clocks, has been one of the greatest aids to accurate observation.

From History of Astronomy by George Forbes

The experimental verification of this fact led him to the important discovery of the isochronism of the pendulum.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" by Various

Thus, in 1720, Julien Leroy occupied himself working out the proper shapes for the inclines to produce this desired isochronism.

From Watch and Clock Escapements A Complete Study in Theory and Practice of the Lever, Cylinder and Chronometer Escapements, Together with a Brief Account of the Origin and Evolution of the Escapement in Horology by Anonymous

The isochronism of the vibrations of the pendulum inferred from this observation was not published or put to practical application in clocks for nearly sixty years afterward.

From Inventions in the Century by William Henry Doolittle

Adjusted to isochronism indicates that the watch functions uniformly during the entire twenty-four hours running.

From Rules and Practice for Adjusting Watches by Walter J. Kleinlein