Columbia subject headings:
Astrolabes--Congresses.
Astrometry--Congresses.
Astronomical photometry--Congresses.
Transit-circle--Congresses.
Harvard subject headings:
Astrolabes--Congresses.
Astrometry--Congresses
Astronomical photometry--Congresses.
Physics
Transit-circle--Congresses.
Princeton subject headings:
Astrolabes--Congresses.
Astrometry--Congresses.
Astronomical photometry--Congresses.
Transit-circle--Congresses.