oa African Yearbook of Rhetoric - The Herschel condition

Volume 2, Issue 2
  • ISSN : 2220-2188
  • E-ISSN: 2305-7785



There is an advanced concept in the design of imaging optics, used to ensure aberration-free images after passage through a series of optical elements, published in 1821 in the by John Herschel and known as The Herschel Condition. The present article has nothing to do with that. Instead, the expression suggested to me that it might be a good occasion to praise a great human being, and interesting to trawl through the extensive Herschel publications and correspondence for personal comments to discover Herschel as a person, rather than as a dry Victorian scientist, albeit one of the leading researchers and philosophers of the nineteenth century. The correspondence is huge, preserved in libraries and archives around the world but made accessible through a project that paralleled a similar effort made for the Charles Darwin letters. The Herschel Calendar lists and summarizes 14 815 letters.

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