RECENT WONDERS OF ELECTRICITY. 679 



when an experiment was tried, to satisfy the French gentleman, we 

 were able to transmit, on a wire between London and Glasgow, no 

 less than 352 words a minute. The growth of telegraphy in this 

 country has been enormous. In 18G9 there were only 2,000 offices 

 open, there are now 5,500 ; there were then only 0,000,000 messages 

 sent a twelvemonth, there are now 30,000,000 ; the income in 1809 

 was 700,000, it is now 1,600,000 ; the number of newspapers and 

 clubs supplied with news was then only 173, it is now 803 ; and there 

 are 326 towns now being supplied with news direct from London. In 

 regard to submarine cables, I have here a box of specimens of the 

 various types of cable laid down, which is well worth examination. 

 Submarine telegraphy has increased during the ten years, from a few 

 hundred miles of cable, to 70,000 miles, which now engirdles the world. 

 There are many other applications of electricity besides telegraphy, 

 such as, for instance, railway-signals. A railway accident recently 

 occurred at Canonbury, where three or four trains were huddled up in 

 a tunnel. I do not know much about the system of signaling used on 

 that railway, but I know a good deal of the system of signaling in 

 use on the London and Southwestern Railway and other lines. The 

 principle of the " block " system is simply that a railway is supposed 

 to be divided into certain sections of a given length, and no two trains 

 are allowed, or ought to be allowed, to be in one section at the same 

 time. If, for instance, the section be a tunnel, such as at Canonbury, 

 and two trains are allowed on it, the risk of collision is great, as re- 

 cently proved ; but, if the block system be thoroughly and efficiently 

 carried out, there ought to be no such accidents. Some twenty years 

 ago, after a good deal of talking, writing, and persuading, I induced 

 the London and Southwestern Railway to adopt the block system. 

 The system in use on the London and Southwestern Railway is my 

 own. A complete set of apparatus is before you, and I will explain 

 its working. A little semaphore is in front of the instrument, which, 

 when down, indicates that all is clear, and, when up, that there is dan- 

 ger, and the train must stop. Suppose the instrument near me is at 

 Waterloo Station, and the other one near Mr. Goldstone is at Vaux- 

 hall. That represents a section of the railway, upon which we want 

 to allow one train only at a time. To ascertain if all is clear at Vaux- 

 hall, I send a warning signal of two beats given twice, indicating " A 

 train is coming," which is acknowledged by a signal of one beat from 

 Vauxhall ; my semaphore arm is down, telling me that the line is 

 clear, and I let the train go on, sending a signal of two beats [this 

 was done] to Vauxhall, to tell him that the train is in. Vauxhall 

 raises the semaphore behind the train to prevent me from sending on 

 another, and I acknowledge his signal, by giving one beat of the bell. 

 The train is now proceeding ; the semaphore arm at this end is up, 

 protecting the train, and I can not, I dare not, send another train until 

 I know that the one now going on has arrived at Vauxhall. It is now 



