Fig. 260. DIAGRAM OF PRINCIPLE OF THE DISPERSION PHOTOMETER.
The cut, Fig. 261, gives a perspective view of Ayrton's Dispersion
Photometer. C is the standard candle, L the concave lens, R the rod for
producing the two shadows on the screen S.
Fig. 261. AYRTON'S DISPERSION PHOTOMETER.
The mirror M is fixed at an angle of 45° with the stem on which it
rotates. The light of the arc lamp is received by the mirror and is
reflected through the lens. The candle holder slides along a graduated
bar C, and at D is an index plate to show the angle at which the spindle
carrying the mirror is set.