Reflecting Circle. Instrument of the sextant type but having a limb graduated through 360°. Besides being able to measure large angles it has the further advantage that, by reversing the
instrument, two observations can be taken - in opposite directions - and any error of the instrument will cancel out when the mean of the two values is taken. Invented by Mayer in 1744. Improved by both Troughton and Borda.
Reflecting Telescope. Telescope in which the image is enlarged by increasing the angle of the rays from it by the use of paraboidal mirrors.
Reflection. A throwing back of light rays, or heat rays. Sometimes applied to sound waves. 2. An image that is observed through reflection.
Refloat. To float again. In Elizabethan days it often meant a 'flowing back'.
Refracting Telescope.One in which the enlargement of the image is obtained by the use of lenses that refract rays from an observed body through an angle larger than that subtended at
the naked eye.
Refraction.Deflection, or bending, of a ray of light, heat or radiant energy, as it passes from surface of one medium into another medium of different density.
Regatta.Originally, a gondola race; now, a gathering of yachts or i boats for racing. Register. Written document or book in which specific information is entered. Specifically applied to a ship's 'Certificate of Registry’.