Carl Pulfrich
Carl Pulfrich (1858-1927)
1927 Obituary[1]
THE LATE DR. C. PULFRICH.
We regret to record the accidental death of Professor Carl Pulfrich, well known by his universal refractometer and by many other optical measuring instruments, brought out by the Zeisswerke of Jena. A strong man and in good health, he was drowned last month, in his sixth-ninth year, while bathing at Timmendorf, on the shores of the Baltic. He held the honorary degree of Dr. Ing.
Carl Pulfrich was born on September 24, 1858, at Burtscheid, near Dusseldorf, and studied at the University of Bonn, where he graduated in 1881. Having enjoyed the friendship of Rudolf Clausius, of thermodynamic fame, he contributed a memoir on the work of Clausius to the Proceedings of the Institution of Civil Engineers, when Clausius died in August, 1888.
In 1890, Dr. Ernst Abbe, who died in 1905, appointed Pulfrich chief of the measuring department of the Zeisswerke, and he retained this position all his life. He soon made his name known by his original designs, improved constructions and his accurate work, as well as by his writings on optical problems. He wrote several books and pamphlets and contributed many papers to various scientific societies, chiefly the Deutsche Physikalische Gesellschaft, and journals, particularly the Zeitachrift fiir Inatrumentenkunde, which included him among its regular collaborators. His last contribution to this journal, dealing with the production of a pure spectrum by the aid of the boundary line of total reflection, appeared in the same September number that briefly announced his death. Total reflection was one of the first problems he had investigated. The Pulfrich universal refractometer was described by him in 1897. Of his other inventions and papers, we may mention his stereo-comparator, his theory of the Zeiss double telescope, his portable photo-theodolite for making coastal surveys from on board ship, his stereo-photogrammeter for contours, telemeters, photographic spectroscopes, interference apparatus, mirror stereoscopes and apparatus for stereoscopic X-ray measurements. He also improved astronomical methods' One of his latest instruments was the step-photometer of 1925 for comparative estimates of the depth of colour and turbidity and the examination of colloids. In 1921 he modified the Abbe microscope.
Respected as a hard and conscientious worker, he was of a genial disposition and most popular with his colleagues. Several instruments designated by his name will serve to keep his work in mind.