DEFLECTION

, the turning any thing aside from its former course, by some adventitious or external cause.

The word is often applied to the tendency of a ship from her true course, by reason of currents, &c, which turn her out of her right way.

Deflection of the Rays of Light, is a property which Dr. Hook observed in 1675. He found it different both from reflection and refraction; and that it was made perpendicularly towards the surface of the opacous body.

This is the same property which Newton calls inflection. And by others it is called diffraction.