from The Century Dictionary.
- noun An instrument designed to measure the relation, brightness, or apparent magnitude of the stars.
from the GNU version of the Collaborative International Dictionary of English.
- noun An instrument for comparing the relative amount of the light of stars.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun An
instrumentdesigned to measure the brightness, relation, or apparent magnitudeof stars.
from Wiktionary, Creative Commons Attribution/Share-Alike License
"astrometer" in which an "artificial star," formed by the total reflection of moonlight from the base of a prism, served as a standard of comparison, he was able to estimate the lustre of the _natural_ stars examined by the distances at which the artificial object appeared equal respectively to each.