Abstract: According to one aspect, an electric toothbrush may include a handle, a brush head, a rechargeable battery, an electric motor, and a pair of electrical contacts. The handle may have a first end region and a second end region defining a longitudinal axis therebetween, the handle defining a volume from the first end region to the second end region. The brush head may include bristles, the brush head releasably securable to the first end region of the handle. The rechargeable battery may be in the volume. The electric motor may be at least partially disposed in the volume, the electric motor in electrical communication with the rechargeable battery, the electric motor in mechanical communication with the brush head. The pair of electrical contacts may be in electrical communication with the rechargeable battery, and the pair of electrical contacts axially and radially spaced from one another, relative to the longitudinal axis.

Abstract: A system for remotely measuring vertical and horizontal winds present in discrete volumes of air at selected locations above the ground. A laser beam is optically focused in range by a telescope, and the output beam is conically scanned at an angle .theta. about a vertical axis. The backscatter, or reflected light, from the ambient particulates in a volume of air, the focal volume, is detected for shifts in wavelength, and from these, horizontal and vertical wind components are computed.

Abstract: A system for remotely measuring velocities present in discrete volumes of air in which a CO.sub.2 laser beam is focused by a telescope at such a volume, a focal volume, and within the focusable range, near field, of the telescope. The back scatter, or reflected light, principally from the focal volume, passes back through the telescope and is frequency compared with the original frequency of the laser, and the difference frequency or frequencies represent particle velocities in that focal volume.