The Sabbaticus Line: Name inscribed on the Eiffel Tower

While in Tournon we saw a statue of Marc Seguin, a famous 18^th century French Engineer.

After visiting the world’s first steam locomotive to carry passengers designed in 1825 by the British brothers George and Robert Stephenson, Seguin managed to acquire, and then sneak, two of Stephenson's steam engines back France for closer inspection. After dismantling one of them and examining their design—a form of industrial espionage—Seguin had an idea of how to significantly enhance the efficiency of Stephenson's design. This idea was the multi-tube boiler: which involved replacing Stephenson’s large water tube within the fire box through which water passed to be heated into steam with a large number of much smaller-diameter tubes. By passing water through these small tubes, Seguin was able to increase the area being heated, significantly increasing the engines ability to produce steam.

He designed two steam locomotives using his multi-tube boiler and also included, amongst other innovations, mechanically driven fans to increase the draught and hence heat of the fire. Using his design, Seguin's was able to increase the speed of the train from 5km/hr to 40 km/hr. A picture of a replica of Seguin's steam engine can be viewed on Wikipedia.

Seguin went onto construct several railways including the Vivarais railway line. A steam train—called the Ardèche Train—now operates on his line today. The steam engine (sadly, not of Seguin’s design) operates for tourists. We took this train journey.

Seguin was also famous for designing suspension bridges in France. By the end of his life he had built and had administered 186 toll-bridges. Seguin wrote a number of books on bridges and locomotives engines. His name is inscribed on the Eiffel Tower: just one of only 72 names.