Not a truck person but it looks like a French Panhard-Chatillon. This was the third four-wheel drive truck adopted
by the French Army in 1914 (the others were the Latil TAR and Renault EG) and it served throughout WW1 and afterwards. They were used to tow heavy artillery pieces
and were part of the establishment of some of the RALTs (Regiment Artillerie Lourdes a Tracteur).
The trailer looks like a La Buire trailer used in WW1 to transport the Schneider CA1 and Schneider CD artillery tractor.
