Popular Science Monthly/Volume 35/October 1889/Obituary Notes
Dr. C. Jessen, naturalist, formerly professor at Greifswald, and more recently at Berlin, has lately died, in his sixty-ninth year.
Prof. Elias Loomis, LL.D., of the Munson chair of Natural Philosophy and Astronomy in Yale University, died August 15th, in his seventy-ninth year. He was graduated from Yale College in 1830, and three years later became a tutor there. He and Prof. A. C. Twining, of West Point, together began the first observations made in this country to determine the altitude of shooting-stars. In 1835 he discovered Halley's comet on its return by means of his own computations of the elements of its orbit. He was the author of text-books covering the whole range of mathematical subjects; of popular treatises on natural philosophy, astronomy, and meteorology; and of many contributions to scientific journals.
Dr. John Percy, a distinguished English metallurgist, died June 20th, aged about seventy-two years. He was appointed Professor of Metallurgy in the School of Mines in 1851, and held the office till 1879. He began his great work on metallurgy in 1861, and continued it in 1864, 1870, and 1880. He received the Bessemer medal of the Iron and Steel Institute for his researches in metallurgy, particularly in iron and steel, in 1877. He was elected a Fellow of the Royal Society in 1847, and President of the Iron and Steel Institute in 1886. He was also distinguished for labors in practical ventilation.