TY  - JOUR
T1  - A System of Train-Signalling, by Which Also Disabled Trains May Telegraph for Assistance without the Aid of Portable Apparatus. 
JF  - Proceedings of the Royal Society of London (1854-1905)
VL  - 8
SP  - 418
EP  - 421
PY  - 1856/01/01/
UR  - http://dx.doi.org/10.1098/rspl.1856.0108
M3  - doi:10.1098/rspl.1856.0108
AU  - Walker, C.
ER  -