A device for inducing the rotation of a plurality of rotors by use of magnetically charged materials includes at least a pair of rotors rotatably mounted. The apparatus includes a vessel having a first end, a second end, and a central portion formed by a light transmissive wall that defines a containment chamber containing a dryness-indicating material, such as a color-changing desiccant or moisture sensitive paper. An abutted member having an objective lens therein is engaged with the lens barrel and a rotatable manually-controlled member is fitted around that lens barrel. , a first element isolation region with high resistance and a second element isolation region which has a contact with the element region and has a conductivity type opposite to that of the source and drain regions of the element region. An actuating shaft of the actuating assembly is preferably mounted via a bearing which is supported on a circumferential face of the camshaft. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time.