1. The third rail or contact conductor is made in sections or blocks of any desired length, which sections are normally dead but become automatically alive when a train enters thereupon, and dead when the train leaves the section. 2. When a train enters upon a section or block it prevents the section back of it from receiving working current. Thus any number of trains following each other will each be deprived of working current when the length of a block back of the train ahead of it, whether that train be running or standing still, thus preventing collisions. 3. A train approaching a switch or drawbridge is automatically arrested the length of a block away from the block containing the switch or draw before a bolt can be withdrawn or a lock released in the latter. 4. No possibility of interference between a possible wandering propulsion current and the functions of any other current. 5. All currents used may be of the same or have any combination of different characteristics. The system is elaborate, providing for safety on and off the trains, economy of current, simplicity and certainty in action, dispenses largely with electrolytic action, and when alternating propulsion current is used the return is confined to the length of the block. It is believed that the system will prevent all danger to passengers and trains from the direct action of the propulsion current. President Roosevelt called the attention of the Interstate Commerce Commission to my electrical and mechanical inventions for making railroading safe. Mechanical Engineering I have done considerable original work in mechanical engineering. In this connection I may mention the well known Robinson Radial Car Truck, which is in quite extensive operation on electric railways. This is the only car truck, I believe, ever designed and constructed on correct mechanical principles. It is so constructed that every axle in the car or train becomes exactly radial to any curve around which it passes, all the axles becoming parallel on straight lines only. This prevents wear and tear and grinding and derailment on curves. It also greatly economizes current. One of these radial cars, in St. Louis, having a 28-ft. body, exclusive of platforms, equipped with a radial truck having a 15-ft. wheel-base and two motors, stopped in the middle of a street corner curve and started with the same power as on a straight line, as shown by careful tests with volt and ammeters. The test was made by officials of the company without my knowledge at the time. I believe this is the coming truck for electric locomotives. (I forward by same mail a catalogue of the Robinson Radial Car Truck, fully illustrated, for the information of the Board.) Coaster Hub