Escapement wheels, which because they lacked a balance spring had no natural "beat", so there was not much incentive to improve the escapement. The great leap in accuracy resulting from the invention of the pendulum and balance spring around 1657, which made the timekeeping elements in both watches and clocks harmonic oscillators, focused attention on the errors of the escapement, and more accurate escapements soon superseded the verge. The next two centuries, the "golden age" of mechanical horology, saw the invention of perhaps 300 escapement designs, although only about 10 stood the test of time and were widely used in clocks
Escapement was recognized as a disturbing influence on the isochronism of the balance. Purchasers no longer buy mechanical watches primarily for their accuracy, so manufacturers had little interest in investing in the tooling required, although finally Omega adopted it in 1990. Although a highly ingenious escapement design, the Daniels coaxial nevertheless still needs lubrication to the lever pallet pivots. In addition, because of its geometry the impulse wheel can only have a limited number of teeth, thus it is necessary to have an extra wheel and pinion in the wheel train the pivots of which also need lubricating. Therefore, the advantages