Born of Catholic parents at Maastriche, Holland, 28 March, 1849; died at Delft 17 March, 1897. At the age of eighteen he was sent to the polytechnical school at Delft, where he obtained the degree of civil engineer after a brilliant examination. A few months later he was appointed a teacher at the Royal Military Academy of Breda, where he published a highly-appreciated textbook on surveying-"Leerboek over landmeten en waterpassen" (Breda, 1879). In 1874 he submitted to the Royal Academy of Amsterdam a treatise on the errors in a plane and in space, and shortly afterwards another on the interpolation formula of Tchebychef, both treatises testifying to an uncommon degree of mathematical intuition. As early as 1878 he was offered the professorship of geodesy and surveying at the polytechnical school at Delft. In 1880 he was elected a member of the Royal Academy of Sciences, in the transactions of which he published a series of important investigations, mostly connected with geodesy: on the calculation of distance and azimuth from longitude and latitude-"Berekening van afstand en azimuth uit lengte en breedte"; concerning the connexion of triangular nets of higher and lower order-"Over de aansluiting van een driehoekennet van lagere orde aan 3 punten van een net van hoogere orde"; on cartographical projections-"Studien van kaart-projectieën"; on the use of Mercator's projection in equatorial triangulation, etc.

Schols however did not confine his interests to geodesy. In connexion with the theory of probability we possess from his hand three communications on the Law of Errors, while of his works on pure mathematics his researches on a semi-convergent series and on errors in logarithmic tables may be mentioned. His activity in civil engineering is well illustrated by the prominent part he took in the publication of the text-book on hydraulic architecture-"Waterbouwkunde", and a detailed investigation into bending moments and shearing stresses in railway bridges. Important national services were rendered by Schols by a conscientious preparation and supervision of the new geographical survey of Holland, which had been undertaken in 1886 by order of the Government. Schols, who had been secretary of the Royal Surveying and Levelling Committee since 1881, threw himself into the work with characteristic ardour. He devised an elaborate plan of proceeding and conducted the operations without allowing the smallest detail to escape him. At the time of his premature death (1897) the greater part of the primary triangulation had been finished.

Unequalled as a teacher he commanded the highest admiration by the masterly way in which he exposed and discussed the most intricate problems, and many scientists of recognized authority were known to take their places on the benches among his pupils. His treatises and calculations recommended themselves by an extreme simplicity, at the same time being classic for their completeness and elegance. In his social intercourse he was amiable and engaging, and in return was universally esteemed and honoured. His energy was remarkable, and the unflinching resolution with which he executed a task, which failing health continually menaced with frustration, cannot be contemplated without admiration. Naturally of a reserved disposition, his habits were simple and his manners unassuming, nor was he ever known to show the slightest vanity or self-esteem on account of the numerous distinctions which were showered upon him; love of truth was his only passion. Three things he always cherished and treasured in the midst of his restless activity: the love of his country, his family, and his religion. He died of consumption at the age of 48.

The article has been composed by the writer from personal reminiscences and from the following articles: VAN DE SANDE BAKHUYZEN, In Memoriam, Charles Mathieu Schols. Verslagen Kon. Akad. (27 March, 1897); WILDEBOER, Ter nagedachtenis van Dr. Ch. M. Schols in Tijdschrift voor Kad. en Landmeetkunde, XIII, ii.

J. Stein.