Although Chicago is known as the Windy City, it is in fact less windy than many other major American cities. Average wind speeds range from 8 miles per hour (13 km/h) in late summer to 12 miles per hour (19 km/h) in spring months.
A flue is a duct, pipe, or opening in a chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors.
The two distinguishing features of Franklin's stove were a hollow baffle (i.e., a metal panel that directed the flow of the fire's fumes) and a flue that acted as an upside-down siphon.