304 THE SCIENTIFIC PAPERS OF 



apart than 2 miles, or 3 miles, special telegraphic stations might 

 be provided. The mpde of signalling adopted in Germany, was to 

 announce a train, at the moment of starting, to the next station, 

 by large bells, placed at intervals of about half an English mile, so 

 that all persons on the line heard when a train had left station A, 

 on its way to station B. Platelayers and switchmen engaged on 

 the line could calculate, within a few seconds, when the train would 

 pass them. The moment the train arrived at station B, the signal 

 Avas sent back to station A that the line was clear, and the general 

 signal was conveyed to station C, and so on along the line. 

 Perhaps such a system of announcing a train all over the line, 

 would not meet with the approval of English railway engineers ; 

 but he thought a system of signalling trains from station to 

 station, and a rule that two trains should never occupy the same 

 section of line together, could be readily introduced without any 

 inconvenience, and he believed, it would effect great saving of time 

 in the working of the lines. 



The arrangement adopted upon several of the German railways 

 was shown by the apparatus he had placed on the table. Small 

 ' bells were fixed at the stations, and at such intermediate points as 

 were thought necessary, and at the moment of leaving, the guard, 

 or other person in charge of the train, turned the handle of the 

 magnetic indicator, which announced at eveiy signalling point 

 that the train had started. Any number of such bells might be 

 rung at the intermediate points. By this signal the train obtained 

 possession of a section of the line, and no other train was allowed 

 to enter that section, until station B had, by another signal, 

 notified that the train had reached it. It was obvious, that such 

 a system might be varied to suit any particular case. 



