It is important not to confuse IMC with IFR (instrument flight rules) â IMC describes the actual weather conditions, while IFR describes the rules under which the aircraft is flying. Aircraft can (and often do) fly IFR in clear weather, for operational reasons or when flying in airspace where flight under VFR is not permitted; indeed by far the majority of commercial flights are operated solely under IFR.
Norbert Rillieux. Norbert Rillieux (1806-1894) was the inventor of the multiple-effect vacuum evaporator, which revolutionized the processing of sugar. He gained recognition as one of the prime architects of the modern sugar industry.
Munroe effect and close relatives. Franz von Baader, in 1792 or 1799, discovered the process of explosive engraving, but this could not have been explosive forming in the modern sense, because he worked with black gunpowder, the detonation velocity of which is too low for what is generally called the Munroe effect.