Hi The most common use was to reverse the process …. you used it to obtain local solar time.
Bob > On Jul 2, 2016, at 3:12 PM, Brooke Clarke <[email protected]> wrote: > > Hi: > > I recently got an Eastern Science Supply Co. demonstration heliostat, that's > to say it's small enough to easily hand hold. I've go it working but have > some questions. > Based on some Waterbury Clock Co. patents I think is was made in the late > 1920s or early 1930s. ESSCo was into astronomy. I got a book they published > "A Manual of Laboratory Astronomy, for use in introductory courses by Harlan > True Stetson Phd, 1928 - but no mention of the heliostat. > http://www.prc68.com/I/ESSCoHeliostat.html > > The base has level vials and an elevation scale for the clockwork driven > lower mirror that's clearly calibrated in latitude. The lower (clockwork > driven) mirror has a pointer to a scale divided into 24 hours, one half black > and the other half white. > > I'm guessing that in order to properly setup this heliostat you need to know > the local mean solar time, i.e. correct for Daylight savings, EOT and your > offset from the time zone meridian. That way you could preset the time then > rotate the base and tilt the lower mirror until the sun's image was centered > on the top mirror. For now I sort of pointed it at north and adjusted both > the lower mirror tilt and the time setting to get the sun along the axis of > rotation. > > Were heliostats also used for looking at stars? i.e. could the Fast-Slow > clock adjustment be used to make the clock work for either solar or sidereal > time? > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > The lesser of evils is still evil. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
