Rector Magnificus, dear colleagues and friends, ladies and gentlemen. This symposium on “The Solar Spectrum” has been arranged in Utrecht, the world-center of spectrophotometry, line intensities and solar physics, in order to celebrate the seventieth birthday of Professor M. G. J. Minnaert. I am glad to use the opportunity of this brief introduction for expressing — as many of us have done already on February 12 — our heartfelt congratulations and our very best wishes for good health, for continued and successful scientific activity and especially for much joy in life and work. Our cordial wishes go just the same with Mrs. Minnaert and the whole family. Their beautiful and original home surely deserves three stars in every astronomers Baedeker!