This is the third of four articles by ‘L.F.’ in which he (or she) ran an eye over the exotic offerings on show at the bicycle salons of the winter of 1905-06. There was not much going on with derailleurs - but plenty of action with every other crazy transmission idea under the sun.
The Peugeot system is the cleverest of the various retro-direct designs, in which you get one forward gear ratio when you pedal forwards and a different forward gear ratio when you pedal backwards. Peugeot managed this cunning feat without using any extra pulley wheels. Instead they had two different sized front-freewheel chainwheels, two different sized fixed rear sprockets and a fearsomely long chain looped around all of these four cogs in a fiendishly clever crossover loop. Shimano FF eat your heart out.
(Source gallica.bnf.fr/ Bibliothèque nationale de France)