000 00779cam a22002053a 4500
001 45179
003 PGUSA
005 20140828084032.0
008 140320s2014||||xxu|||||s|||||000 | eng d
040 _aPGUSA
_beng
042 _adc
100 1 _aAssociation, American Railway
245 1 4 _aThe Invention of the Track Circuit :
_bThe history of Dr. William Robinson's invention of the track circuit, the fundamental unit which made possible our present automatic block signaling and interlocking systems
_h[electronic resource] /
_cAmerican Railway Association
260 _bProject Gutenberg,
_c2014
506 _aPublic domain in the USA.
516 _aElectronic text
830 0 _aProject Gutenberg
_v45179
856 4 0 _uhttp://www.gutenberg.org/ebooks/45179
942 _cEB
999 _c274430
_d274430