Thierry, in the second picture you can see my splitting axe on the side. It's a Fiskars axe, about 4lbs, which is the nicest splitting axe I have used, good steel and balance. I wonder how the hollow carbon fiber handle will hold up over time.
The wood in the picture is 32", I am preparing it to fit inside a barrel charcoal retort, also why it is split so small. It is black poplar (Balsam poplar / balm of Gilead) I believe it is common in northern Europe also. Here it isn't valued as firewood, but it was in my way, and splits very well when frozen. The trembling aspen (white poplar) I cut in the same stand I am cutting and splitting in 4ft lengths. Depending on how hard the wood is to split, 32" may be better, as it still divides into standard 16" fire wood.