b. 11 September 1816 Weimar, Thuringia, Germany
d. 3 December 1888 Jena, Saxony, Germany
After completing his early education in Weimar, Zeiss became an apprentice to the engineer Dr Frederick Koerner. As part of his training, Zeiss was required to travel widely and he visited Vienna, Berlin, Stuttgart and Darmstadt to study his trade. In 1846 he set up a business of his own, an optical workshop in Jena, where he began manufacturing magnifying glasses and microscopes. Much of his work was naturally for the university there and he had the co-operation of some of the University staff in the development of precision instruments. By 1858 he was seeking to make more expensive compound microscopes, but he found the current techniques primitive and laborious. He decided that it was necessary to introduce scientific method to the design of the optics, and in 1866 he sought the advice of a professor of physics at the University of Jena, Ernst Abbe (1840-1905). It took Zeiss until 1869 to persuade Abbe to join his company, and two difficult years were spent working on the calculations before success was achieved. Within a few more years the Zeiss microscope had earned a worldwide reputation for quality. Abbe became a full partner in the Zeiss business in 1875. In 1880 Abbe began an association with Friedrich Otte Schott that was to lead to the establishment of the famous Jena glass works in 1884. With the support of the German government, Jena was to become the centre of world production of new optical glasses for photographic objectives.
In 1886 the distinguished mathematician and optician Paul Rudolph joined Zeiss at Jena. After Zeiss's death, Rudolph went on to use the characteristics of the new glass to calculate the first anastigmatic lenses. Immediately successful and widely imitated, the anastigmats were also the first of a long series of Zeiss photographic objectives that were to be at the forefront of lens design for years to come. Abbe took over the management of the company and developed it into an internationally famous organization.
fl. 11th century China
In his treatise Wu Jing Zong Yao, compiled with an assistant c. 1040, he wrote down the first formula for gunpowder to be printed and published in any civilization, although the essentials of the mixture had been known in China for just over a century. The text describes several military applications of gunpowder, with an incendiary or, in one case, a toxic chemical rather than an explosive effect; the saltpetre content was too low for the latter, but it was steadily increased over the years.
b. 8 July 1838 Konstanz, Germany
d. 8 March 1917 Berlin, Germany