lībrāmentum, i, n. [libro], that which gives to any thing a downward pressure; weight, gravity.
I Lit.: plumbi, Liv. 42, 63, 4.—
B A fall, descent of water: libramentum aquae, Plin. 31, 6, 31, § 57: quod libramentum cum exinanitum est, suscitat et elicit fontem, cum repletum, moratur et strangulat, of a spring that alternately rises and falls, Plin. Ep. 4, 30, 10: inferiore labro demisso ad libramentum modicae aquae receptae in fauces, palpitante ibi lingua ululatus elicitur, of the croaking of frogs, Plin. 11, 37, 65, § 173.—
II Transf.
A A level surface, horizontal plane : extremitatem et quasi libramentum, in quo nulla omnino crassitudo sit, * Cic. Ac. 2 ( Luc. ), 36, 116: sub eodem libramento stare, Sen. Q. N. 1, 12, 1: usque ad libramentum summi fornicis, Ael. Gall. ap. Paul. ex Fest. p. 206 Müll.—
B Evenness, equality : ventorum hiemalium et aestivorum, Col. 1, 5, 8—
C A straight line : si recto libramento inter solem terrasque media (luna) successit, Sen. Ben. 5, 6, 4: libramentum finale, a boundary line , Amm. 15, 4, 4.—
D A weight for balancing or giving motive power (ballista): ferrea manus cum injecta prorae esset, gravique libramento plumbi recelleret ad solum, Liv. 24, 34, 10: arietem admotum nunc saxis ingentibus nunc libramento plumbi gravatum ad terram urguebant, id. 42, 63, 4 Weissenb.: late cladem intulisset, ni duo milites vincla ac libramenta tormento abscidissent, Tac. H. 3, 23.