10-Letter Words Containing: HELIO

• protozoa with spherical bodies and stiff radiating pseudopods

• an apparatus for sending telegraphic messages by using a mirror to turn the sun's rays off and on

• signal by means of a mirror and the using the sun's rays

• duplicator consisting of a gelatin plate from which ink can be taken to make a copy

• the worship of the sun

• a message transmitted by means of the sun's rays

• green chalcedony with red spots that resemble blood

• an instrument used to measure the angular separation of two stars that are too far apart to be included in the field of view of an ordinary telescope

• periapsis in solar orbit; the point in the orbit of a planet or comet where it is nearest to the sun

• A device that includes a plane mirror which turns so as to keep reflecting sunlight toward a predetermined target, compensating for the sun's apparent motions in the sky. The target may be a physical object, distant from the heliostat, or a direction in space, and is almost always stationary relative to the heliostat, so the light is reflected in a fixed direction.