Labuan, in 1867 ; of the West Afri can settlements, in 1872; of the Bahamas, in 1873 ; of the Wind- ward Islands, in 1875; of Hong- kong, in 1877; and of the colony of Mauritius, in Dec. 1882. He was created a Knight Commander of the Order of SS. Michael and Georffe, in April, 1880. He contri- buted papers to the " Proceedings" of the Eoyal Society and British Association, to the Philosojlhical Magazine, the Contemporary Review ^ and the Nineteenth Century ; and he published, in 1883, a volume on " Raleigh in Ireland, with his Let- ters on Irish Affairs, and some contemporary Documents." He has been hon. secretary to the Mathe- matical section of the British As- sociation, and chairman of the Repression of Crime section of the Socifd Science Congress.
HENNESSY, William Maitn- SKLL, was born at Castlegregory, co. Kerry, in 1828, and educated at private schools. He was one of the writers of the "Nation newspaper from 1853 to 1856, in which latter year he obtained, by public compe- tition, an appointment in Dublin Castle. Mr. Hennessy is an eminent Celtic scholar and archae- ologist. He was promoted for his efficiency to a responsible position in the Public Record Office of Ire- land. He is a member of the Royal Irish Academy, to the "Proceed- ings " of which he has contributed several important papers, including a remarkable treatise on the
- ' Ancient Irish Goddess of War,"
and another on the Irish system of " Trial by Ordeal." Mr. Hennessy has edited, besides other works, the "Chronicon Scotorum," and the " Annals of Loch-Key," published in the Rolls* series of National Chronicles. He is one of the writers of the Revue Celtique, and has also contributed to the Revue Critique, Kuhn's Zeitschrift, and to the Beitrdge zur vergl. Sprachjort- chung. He is one of the writers of the Academy, in which he published
a remarkable article on the " Ossi- anic " controversy.
HBNRICI, Olaus, Ph.D., was bom March 9, 1840, at Meldorf, in Holstein, and received his early education in the gymnasium of his native town. In 1856 he left Mel- dorf in order to study for some years in the workshops of a me- chanical engineer. In 1859 he pro- ceeded to the Polytechnic School in Karlsruhe, where he remained until 1862, when he entered the Univer- sity of Heidelberg. Here, in 1863, he graduated with special honours as Ph.D. Dr. Henrici next pro- ceeded to Berlin in order there to prosecute his mathematical studies. In 1865 he became private docent or tutor in the University of Kiel, but left soon afterwards for Lon- don. In 1869 Dr. Henrici was ap- pointed Professor of Pure Mathe- matics in the University College, London. In 1868 he was elected a member, and in 1869 one of the vice-presidents of the London Mathematical Society. The learned Professor is the author of the fol- lowing papers, " Bemerkung zu ' Hesse ' Zerlegung der Bedingung f fir die GleicWieit der Hauptexen eines auf einer Oberflftche zweiter Ordnimgliegenden Kegelschnittes" (in Crelle's Journal, vol. 64, 1864) ; '* Transformation von Differential- ausdriicken erster Ordnung zweiten Grades mit Httlfe der verallge- meinerten elliptischen Co-ordina- ten" (Crelle's Journal, vol. be v., 1865^ ; " On certain Formulae con- cerning the Theory of Discrimin- ants ; with Applications to Dis- criminants of Discr., and to the Theory of Polar Curves" (in the " Proceedings " of the London Mathem. Society, vol. ii., read in Nov., 1868); and "On Series of Curves, especially on the Singu- larities of their Envelopes: with Applications to Polar Curves," also in the " Proceedings " of the Lon- don Mathematical Society, vol. ii.
HENRIQUEL-DUPONT, Louis- PiEBRE, engraver, was born in