The city magistrates’ technological challenge was taken up by hydraulic engineer François Le Rat, assisted by André Leclerc. François Le Rat, who had played a role in the purchase of the first Dutch pump when he was fire chief for the City of Rouen, had analysed all its defects, noting above all that the impregnated-leather covered wooden pistons were not sufficiently sturdy and watertight.
Before the existence of leather tubes, François Le Rat perfected a new flexible connection system between the pump and the hose.
The brass pipe carrying water to the hose was composed of a fixed vertical section with a system of nozzles which made it possible to orient the jet from the hose in all directions. The hose itself was screwed directly onto a nozzle.