a. (sb.) [f. TRI-, after BI-UNIAL.] Applied to a magic lantern having three optical tubes combined in one: also ellipt. as sb.
1897. Daily News, 3 Dec., 5/5. A lecturer … who was provided … with what was described as ‘a magnificent triunial.’
a. (sb.) [f. TRI-, after BI-UNIAL.] Applied to a magic lantern having three optical tubes combined in one: also ellipt. as sb.
1897. Daily News, 3 Dec., 5/5. A lecturer … who was provided … with what was described as ‘a magnificent triunial.’
