Although a little outside the scope of these notes, the writer would emphasize that in the English colonies and in South America (especially, however, the former) the track circuit is being much used and its value appreciated. Automatic signaling is in use in Victoria, Queensland, South Australia and New South Wales. The operating conditions in these countries no doubt much resemble American circumstances and the adoption of automatic signals is a natural development. Summing up, the writer would say, that the earliest experiments of W. R. Sykes in England are probably as old as those of Dr. Robinson, but owing to the different circumstances in which the former inventor was placed, he had little encouragement to continue them and thus American development at first went on far ahead of English, while owing to the vastness of the American continent it must always present a larger field to the signal engineers' ingenuity and activity. In later years, however, the English signalmen awoke to the importance of the question and installations were constructed which, if smaller, showed as great a degree of technical perfection as any in America. The future will doubtless see more such installations. It is not known to the writer whether anyone on the continent had the idea of a track circuit as far back as Sykes' or Robinson's experiments or when the first attempts were made. It would require much investigation to find this out. Track circuit possibilities are now well known there and no doubt its use will extend, but in certain countries, notably Germany and Switzerland, there are local circumstances which act rather strongly against it at present. The writer cannot give statistics on the subject now. There are some figures which he possesses, but they should be verified and amplified before being used by the Signal Section for publication. The preceding notes are, he is too fully aware, very incomplete and general, but he hopes they may be of some present use. End of the Project Gutenberg EBook of The Invention of the Track Circuit, by American Railway Association