qsy-complains-a-lot:

Detaille dress helmet Mle1912

Cuir bouilli burgonet-type helmet, brass rim, jugular strap and ventilated comb.
Edouard Detaille, a famous military illustrator, designed this helmet as “the Frenchest of the helmets of old” to be part of his new uniform prototype. It was not considered fit for frontline service then due to its high weight, although the Adrian Mle1915 steel helmet that ended up being adopted was just as heavy.

The French army in the 1900′s was aware that a less conspicuous uniform was needed, but was very much unwilling to part ways with the good old red pants of yore. This led to various modern uniform ideas to fall in development hell, never to see the light of day until WW1 finally nailed shut their coffins.