The Teakettle is one of the home inventions designed by Gadget.
It was used for boiling water (what else?).
The Teakettle was made from a sawed off bolthead with a metal
half-sphere soldered to it. There is a round hole at the top of the half-sphere.
In the spout of the Teakettle Gadget has built in a whistle, which
gives a signal when the water is boiling up.