Experimenting on a raft anchored on the river Elbe, Alfred Nobel tries to make nitroglycerine safer to handle. Finds that the addition of kieselguhr turns nitroglycerine into a dough that can be kneaded, and calls it "dynamite".
The raft is on the Elba river.
The raft is on the river Elbe. The system was confused by the spelling.
( z1 raft :location ( z2 river :name ( z3 name :op "Elba" :op "River" ) ) )