Abstract: Road surface condition detection system comprising light projector means for projecting light including the infrared region of the spectrum to a road surface to sense the condition thereof, the infrared having wavelengths at which the reflectance of snow is smaller than that of the road surface in a dry condition, light receiving means for receiving light reflected from the road surface, comparisons means for comparing the output signals generated from the light receiving means with reference signal levels corresponding to dry, wet, snowy and frozen conditions, and judging means for judging the road surface to be one of the conditions in accordance with results of comparison.

Abstract: In a microscope with a motor-driven objective turret, an intermediate position is provided between each two adjacent primary turret positions. This intermediate position enables manual operations to be carried out on the objectives in the objective turret, in a convenient manner, before viewing. Automatic means are provided for switching off the motor in both the primary and the intermediate turret positions.