( ( Air pressure ) ( ( is ( measured ( in ( ( torr , ) ( named ( after ( ( Evangelista Torricelli ) ( who ( ( invented ( the barometer ) ) ( in 1643 ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Air) (NN pressure)) (VP (VBZ is) (VP (VBN measured) (PP (IN in) (NP (NP (NN torr)) (, ,) (VP (VBN named) (PP (IN after) (NP (NP (NNP Evangelista) (NNP Torricelli)) (SBAR (WHNP (WP who)) (S (VP (VBD invented) (NP (DT the) (NN barometer)) (PP (IN in) (NP (CD 1643))))))))))))) (. .)))
Air pressure is measured in torr, named after Evangelista Torricelli who invented the barometer in 1643.
(ROOT (S (NP (DT A) (NN torr)) (VP (VBZ is) (NP (NP (DT a) (NN unit)) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN pressure)))))))) (. .)))
A torr is a unit used to measure pressure.