Die Beugungserscheinungen: a Tribute to F. M. Schwerd's Monumental Work on Fraunhofer Diffraction

The painstaking labors of a professor in Speyer, Germany, produced a most remarkable work on Fraunhofer diffraction over a century ago. Die Beugungserscheinungen by F. M. Schwerd (published in Mannheim in 1835) was profusely illustrated with excellent drawings of the calculated amplitude and intensity distributions of the Fraunhofer patterns of many interesting apertures and arrays. Some of these were carefully hand-colored to show the spectral distribution produced with white light. This paper provides a brief biographical sketch of Schwerd, and presents the beautiful experimental verification, which has recently been obtained with the aid of a computer generated diffraction plate, of the astounding accuracy of one of his color drawings.