• Webster's Revised Unabridged Dictionary
    • n Heliostat An instrument consisting of a mirror moved by clockwork, by which a sunbeam is made apparently stationary, by being steadily directed to one spot during the whole of its diurnal period; also, a geodetic heliotrope.
    • ***
Century Dictionary and Cyclopedia
    • n heliostat An instrument consisting of a mirror carried by clockwork in such a way as to reflect the sun's rays in a fixed direction. The name is also improperly applied to a porte-lumière.
    • ***
Chambers's Twentieth Century Dictionary
    • n Heliostat hē′li-o-stat an instrument by means of which a beam of sunlight is reflected in an invariable direction.
    • ***


Webster's Revised Unabridged Dictionary
Helio-, + Gr. placed, standing, fr. to place, stand: cf. F. héliostate,
Chambers's Twentieth Century Dictionary
Gr. hēlios, sun, statos, fixed—histanai, to stand.


In literature:

In a short time we might earnestly wish for a centrifugal apparatus or a heliostat.
"More Letters of Charles Darwin Volume II" by Charles Darwin
It is a good object by which to adjust my hand heliostat, which I describe below.
"The Art of Travel" by Francis Galton
No day that you can't use a heliostat; Sunlight is eternal in Medicine Hat.
"The So-called Human Race" by Bert Leston Taylor
In the absence of a heliostat it is more convenient to obtain a point of light with the aid of a lens of short focus.
"Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4" by Various
"St. Nicholas Magazine for Boys and Girls, Vol. 8, May 1886, No. 7." by Various
Foucault's heliostat reflects the rays horizontally in any required direction.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2" by Various

In news:

Solar Field One, its respective tower, and heliostat installation.
Workers install a heliostat on a pylon in Solar Field One.
View north of Ivanpah Solar showing all three solar fields with heliostat installation complete in Solar Field One in the foreground.
Physicists John Vallerga, right, and Pat Jelinsky talk about the heliostat they designed at their offices at UC Berkeley in Berkeley, Calif, Thursday, May 3, 2012.
A rendering of how heliostats will look on the proposed Ivanpah Solar Energy Generating System site.
Solar power tower and surrounding heliostats at the Gemasolar concentrating solar power plant in Spain.
Arranging heliostats at certain angles could reduce land footprints for big solar plants.

In science:

The prototype was set-up at the old Utrecht observatory “Sonnenborgh”, next to the heliostat that has been used for pioneering work on the (“first”) solar spectrum (Minnaert et al. 1940).
The Prototype of the Small Synoptic Second Solar Spectrum Telescope (S5T)
The heliostats will be divided into three sectors and Cherenkov light from each sector will be reflected onto a separate 2 m diameter secondary mirror.
Development of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)
PMT may be positioned so that it sees light from only one heliostat.
Prototype Test Results of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)
PMT sees only the surface of the heliostat and not the ground around it.
Prototype Test Results of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)
PMTs when the heliostats are pointed towards the sky.
Prototype Test Results of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)