What is Diving bell?
[[File:Franz Kessler Wasserharnisch 1616.gif|thumb|Franz Kessler Wasserharnisch 1616]] A '''diving bell''' was an early system for [[underwater diving]]. The basic idea of a bell is that a hollow object, even with an open bottom, will hold air when put under water (this can be seen with a glass in a sink). If the bell is heavy enough it will sink below the water. A swimmer can be inside the bell and breathe, or hold his breath and swim outside the bell for a short time, and come back to the bell to breath again. The idea had been around for a long time, but became useful in the 1600s.<ref>{{cite web|title=A Brief History of Diving: Free Divers, Bells and Helmets Part I|url=http://www.dtmag.com/Stories/Dive_History/12-02-2feature.htm|author=Alex Brylske|publisher=Dive Training|access-date=14 April 2015}}</ref> [[Scuba diving]] has mostly replaced diving bells although they are still used sometimes. ==References== {{reflist}} {{stub}} [[category:diving]]