Hermann August Hagen was born on May 30, 1817, in Königsberg, Prussia.

He was a German physician, entomologist, and author. He studied medicine at the University of Königsberg (M.D., 1840) and then in Berlin, Vienna, and Paris. In 1843, he returned to Königsberg, entered into the general practice of medicine, and for three years was the first assistant at a surgical hospital. He became interested in dragonflies and in 1839, he published his first paper “List of the Dragonflies of East Prussia”. Between 1855 and 1860, Hagen published several volumes of his monograph on termites "Monographie der Termiten". In 1867, he began working as an assistant in entomology at the Museum of Comparative Zoology at Harvard University and helped establish a department of entomology there. He became an assistant professor in 1868 and a full professor in 1870, the first appointment of a professor of entomology in any American institution. From 1868 to 1890, he systematically arranged and catalogued Harvard’s insect collections. He was a member of the American Academy of Arts and Sciences, the American Philosophical Society, and the American Entomological Society. He founded the Cambridge Entomological Club. In 1863, he received the honorary degree of Ph.D. from the University of Königsberg.

In 1851, he married Johanna Maria Elise Gerhards (1832-1917). He died on November 9, 1893, in Cambridge, Massachusetts.

Arnold Hague was born on December 3, 1840, in Boston, Massachusetts.

He was an American geologist. In 1863, he received his degree in chemistry from Yale’s Sheffield Scientific School and continued his studies in Göttingen, Heidelberg, and Freiberg in Saxony. In 1866, he returned to the United States and was appointed assistant geologist on the U. S. Geological Exploration of the 40th parallel under Clarence King. Between 1867 and 1872, they systematically and comprehensively mapped and assessed the topography, geology, and natural resources of 87,000 square miles of western lands flanking the transcontinental railroad. They completed fieldwork in 1872 and prepared their folio atlas and the final reports as parts of the Engineer Department Professional Paper 18. In 1877, Hague received the appointment of government geologist of Guatemala and in 1878, he was engaged by the Chinese government to examine gold, silver, and lead mines in northern China. He became a geologist of the U. S. Geological Survey in 1879 and in 1883, he was made geologist of the Yellowstone National Park, assigned to the study of the geysers. He was elected to the National Academy of Sciences in 1885. He received an honorary Sc.D. degree from Columbia University in 1901, and an LL.D. degree from Aberdeen University. He was vice president of the International Congresses of Geologists held in Paris in 1900, in Stockholm in 1910, and in Toronto in 1913. He became president of the Geological Society of America in 1910.

In 1893, he married Mary Anne Bruce (Robins) Howe (1850- ). He died on May 14, 1917, in Washington, D.C.

George Hague was born on January 13, 1825, in Rotherham, Yorkshire, England.

He was a bank agent and author. He immigrated to Canada in 1840. He worked at the Bank of Toronto. In the 1880s, he became a General Manager of the Merchants Bank of Canada in Montreal. The bank came close to failing during the depression of the 1870s but was saved by Hague’s competent management. He also served as a Chairman of the Civil Service Commission of Canada in Ottawa in the 1890s. He wrote several books on bank management and commerce.

In 1852, he married Sarah Cousins (1820–1900) and in 1902, he remarried Mary Frances Mitcheson (1874–1919). He died on August 26, 1915, in Montreal, Quebec

Otto Hahn was born on July 13, 1828, in Ellwangen, Wurttemberg, Germany.

He was a German petrologist, geologist, lawyer, and author. He started his career as a lawyer. He eventually left the legal profession for the natural sciences. The University of Tübingen awarded him a doctorate for his participation in the Eozoön canadense controversy ("dawn animal"), an enigmatic Archaean fossil described in 1864 from Canadian limestone formations, believed to be some sort of gigantic microorganism that predated all other known fossil organisms. In 1880, after careful investigation of some collected rock samples, Hahn changed his mind and reclassified Eozoön as ancient algae, renaming the fossil Eophyllum ("dawn plant"). He published his studies and observations of sedimentary rocks in the book "Die Urzelle" (1879). He also studied meteorites and published his discoveries in the book "Die Meteorite (Chondrite) und Ihre Organismen" (1880).

In 1865, he married Rosine Rosa Friederike Schloz (1842–1923). He died on February 23, 1904, in Buffalo, New York.