The Collaborative International Dictionary
Halometer
Halometer \Ha*lom"e*ter\ (h[.a]*l[o^]m"[-e]*t[~e]r), n. [Gr. "a`ls, "alo`s, salt + -meter.] An instrument for measuring the forms and angles of salts and crystals; a goniometer.
Wiktionary
halometer
n. An instrument for measuring the forms and angles of salts and crystals.