This escapement will be found in nearly all the grandfather clocks in connection with a seconds pendulum. It is a good time-keeper, runs well, wears well, stands some rough handling and will keep going even when pretty well covered with dust and cobwebs; so it is used more than all the numerous types ever invented. Figure 28 gives the general American form of the "anchor" which is made by bending a strip of steel; but it is not the best form, as the acting surfaces of the pallets are straight. It is, therefore, inferior to Fig. 27 where the acting surfaces are curved, since these curves give an easier "recoil." This recoil is the slight motion _backwards_ which the escape wheel makes at each tick. The "dead beat" escapement is shown in Fig. 29, and is used in clocks of a high grade, generally with a seconds pendulum. It has no recoil as you can easily see that the surfaces O O on which the teeth fall, are portions of a circle around the center P. The beveled ends of these pallets are called the impulse surfaces, and a tooth is just giving the little push on the right-hand pallet. It is found in good railroad clocks, watch-makers' regulators and in many astronomical clocks. These terms are merely comparative, a "regulator" being a good clock and an "astronomical," an extra good one. Figure 30 gives the movement of a "remontoir" clock in which the dead beat shown is used. The upper one of the three dials indicates seconds, and the lever which crosses its center carries the large wheel on the left. [Illustration: Fig. 29--Dead Beat Escapement] [Illustration: Fig. 31--Remontoir Clock by James Arthur] [Illustration: Fig. 30--Remontoir Clock Movement]