But the eye is tolerant of small changes in the focal adjustment which sensibly affect the scale-value.
She'd forgotten how hard the adjustment had been from immortal to mortal world.
The outer pair receive the strain of the rotator, and the inner are for adjustment and to prevent lateral movement.
The proper adjustment of the reins is the next thing to be attended to, and as the management of these depends so much upon the seat being firm and independent of the bridle the acquisition of a firm seat is certainly half-way towards the acquirement of good hands.
The effect of each of the elements of the grating is then the same; and, unless this vanishes on account of a particular adjustment of the ratio a: d, the resultant amplitude becomes comparatively very great.