This photo shows a barometer on frenchman Bernard Poitau's boat "Anticylone" as he takes part in the Vendee Globe, the solo non-stop round the world yacht race, on the Virtual Regatta sailing race ...

Add Yahoo as a preferred source to see more of our stories on Google. A barometer is a tool meteorologists use to measure atmospheric pressure, which is defined using millibars (mb). The layers of air ...