Around 1675, Giovanni Domenico Cassini observed a dark gap in which planet's main rings?

In the 1620s, Italian traveler Pietro della Valle brought Europe copies of inscriptions from Persepolis in which wedge-… Around 1627, Myles Standish and which husband of Priscilla Mullins helped found the town of Duxbury, Massachusetts? Around 1630, Jan Baptist van Helmont identified which gas given off by burning wood, calling it "gas sylvestre"? Around 1668, Isaac Newton built the first practical reflecting version of which instrument? Around 1684, Jules Hardouin-Mansart completed which famous room at Versailles, called the Galerie des Glaces in French? Around 1700, Bartolomeo Cristofori of Florence invented which instrument? In the early 1700s, who set the freezing point of water at 32 degrees and the boiling point at 212? Around 1720, which Mississippi port became the capital of France's Louisiana territory?