Abstract
THE council of the Physical Society has awarded the eleventh Duddell Medal to Mr. Harold Dennis Taylor. This medal is given “to persons who have contributed to the advancement of knowledge by the invention or design of scientific instruments, or by the discovery of materials used in their construction”. Mr. Taylor has lived and worked in a period which must always be regarded as of the first importance in the development of optical instruments. The work of Abbe and Schott may be said to mark the beginning of the modern period in lens construction. At this time, Dennis Taylor was the optical manager of Thomas Cooke and Sons, of York, a firm celebrated for its astronomical and surveying instruments. Large astronomical refractors of that period suffered from a serious defect, the so-called secondary spectrum, a residual defect remaining when the normal conditions for the removal of chromatic aberrations have been satisfied. Taylor removed this defect by employing three glasses, and with rare skill and insight devised an objective in which not only the purely optical problem was solved, but also the important practical problems of giving accuracy of form to large lenses of different shapes, and, allowing for their deformation in use. In these first triple apochromats, the colour correction is so good, and is so successfully combined with the other fine corrections needed, that the same instruments may be used both for visual and for photographic work. A number of large telescopes of this type are in regular use, among them two, of apertures 12 in. and 12 in., at Cambridge; other 12 in. instruments of this design are in use at Rio de Janeiro and at Kodaikanal in India.
Article PDF
Rights and permissions
About this article
Cite this article
Mr. H. Dennis Taylor. Nature 133, 442 (1934). https://doi.org/10.1038/133442b0
Issue Date:
DOI: https://doi.org/10.1038/133442b0