( ( School ( of ( ( ( ( Physics ( Historical ( Collection ( Delezenne 's ) ) ) ) ( Circle ( Philip Harris ) ) ) , ) ( ( early ( 20th century ) ) ( This instrument ) ) ) ) ) ( ( demonstrates ( how ( ( an ( electric current ) ) ( is ( produced ( in ( ( a coil ) ( of ( ( wire ( -LRB- ( ( on ( the ( wooden ring ) ) ) -RRB- ) ) ) ( when ( ( the coil ) ( is ( rotated ( through ( ( the ( earth 's ) ) ( magnetic field ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP School)) (PP (IN of) (NP (NP (NP (NNP Physics) (NNP Historical) (NNP Collection) (NNP Delezenne) (POS 's)) (NNP Circle) (NNP Philip) (NNP Harris)) (, ,) (NP (NP (JJ early) (JJ 20th) (NN century)) (NP (DT This) (NN instrument)))))) (VP (VBZ demonstrates) (SBAR (WHADVP (WRB how)) (S (NP (DT an) (JJ electric) (NN current)) (VP (VBZ is) (VP (VBN produced) (PP (IN in) (NP (NP (DT a) (NN coil)) (PP (IN of) (NP (NP (NN wire)) (PRN (-LRB- -LRB-) (PP (IN on) (NP (DT the) (JJ wooden) (NN ring))) (-RRB- -RRB-)) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN coil)) (VP (VBZ is) (VP (VBN rotated) (PP (IN through) (NP (NP (DT the) (NN earth) (POS 's)) (JJ magnetic) (NN field)))))))))))))))) (. .)))
School of Physics Historical Collection Delezenne's Circle Philip Harris, early 20th century This instrument demonstrates how an electric current is produced in a coil of wire (on the wooden ring) when the coil is rotated through the earth's magnetic field.
(ROOT (S (NP (DT The) (JJ magnetic) (NN field)) (VP (VBD produced) (PP (IN by) (NP (NP (DT a) (NN current)) (PP (IN in) (NP (DT a) (NN wire) (NNS moves))))) (PP (IN in) (NP (JJ concentric) (NNS circles)))) (. .)))