In each grenadier or carabineer company of French line and light infantry, there were four sapper soldiers and a sapper corporal, who had been trained in basic engineering.
They usually wore a standard uniform of a grenadier, with emblems on the sleeves in the form of crossed axes, white leather gloves with bells and an apron.
It's interesting to note that a broad beard was an obligatory element of sapper uniform. The sapper equipment included an axe and a special field-engineer cutlass. They were armed with dragoon rifles and sometimes a brace of pistols.
Sappers were supposed to destroy and build fortifications, and also help soldiers destroy fences and punch holes through the walls of buildings. Sometimes it was necessary for them to use black-powder charges.