544,886. Indicating apparatus ; speedometers. GENERAL MOTORS CORPORATION. Aug. 7, 1940, No. 12666. Convention date, Aug. 28, 1939. [Classes 106 (iii) and 106 (iv)] A measuring and indicating instrument such as a speedometer is provided with a movable pointer illuminated by internally reflected light which over different ranges of movement is illuminated by different colours. In the form shown in Fig. 2 a speedometer casing 27 is supported on a flange 25 of a casing 11 on which is seated a plate 15 carrying an annular transparent dial 17 held in a bezel 23 by a retaining ring 19 and cover glass 21. The plate 15 has apertures 45 through which light from diametrically opposed lamps 43 illuminate the dial by internal reflection. Co-operating with the dial is a pointer 47, Figs. 2, 4 and 5, of transparent material with a central hub 49 having a bush 57 with a tapering hole for the reception of the end of the spindle 67 of the speedometer. The hub 49 is formed with an opening 69 having an inclined outer surface 73 so that light passing through an aperture in a retaining washer 61 is reflected by the surface 73 along the arm 51 of the pointer. The plate 15 is formed with a central aperture below which is arranged a stationary plate 85 with coloured portions 87, 89 and 91 of green, amber and red respectively, and an elongated light-transmitting rod 79 with a tapered hub 83. Light from the lamps 43 is transmitted through the rod by internal reflection and is reflected at the surface 83 in a direction parallel to the axis through the coloured portions of the plate 85 to the pointer 47 the pointer changing colour in dependence on the different speed ranges.