The teacher found the boys out, and forbade their studying German during school-hours, but allowed them to do so at recess and noon, when he also took a part in the exercise.
In 1826 Haldeman was taken to Harrisburg, to the classical school of Dr. John Miller Keagy, a "great teacher," who, besides the classical languages, "knew Hebrew, German, and French. He had a taste for the natural sciences, and in the absence of class-books he taught orally in an excellent conversational style." He remained two years at this school, and was then sent to Dickinson College, where his scientific tastes were encouraged by Professor Rogers, afterward State geologist. The stereotyped course of study of the college was not consonant with his own views of how his faculties should be trained, and he left the institution after two years, to take the superintendence of his own studies. He became ostensibly engaged with his father in conducting a saw-mill, but spent much of his time in field-studies, and with his books, concerning which he wrote at the time: "I developed a taste for rainy weather and impassable roads; then I could remain undisturbed in the perusal of my books, a supply of which I kept in a back office, where I retired as soon as the sky looked threatening." In 1833-'34 he attended the lectures of the medical department of the University of Pennsylvania, but without any design of becoming a physician. In 1835 he was married to Miss Mary A. Hough. Shortly afterward he removed to Chickies, Pennsylvania, to the house which he occupied till the end of his life, and became a silent partner in the iron business conducted by his brothers, Dr. Edwin and Paris Haldeman. In connection with this business he wrote two papers for "Silliman's Journal," on "Smelting Iron with Anthracite Coal," and edited, in 1855, a revision of Taylor's "Statistics of Coal." "In his residence at Chickies," says Dr. D. G. Brinton, in his memorial before the American Philosophical Society, "books and cabinets accumulated under his laborious hands, only to be scattered again and give place to others when his insatiable appetite for knowledge led him into new fields of investigation. For forty-five years he spent most of his time in his library, where, in his vigorous manhood, he worked sixteen hours a day. For, though he accepted several professorships, and delivered a number of courses of lectures, he did so with reluctance, preferring to be master of his time, and to spend it in the quiet of home."
He received from Professor Rogers an appointment as assistant on the Geological Survey of New Jersey in 1836, and of Pennsylvania in 1837. His field of work in Pennsylvania embraced that part of the State lying between the Blue Mountain and the South Mountain, the most important division, geologically, in the State. While engaged upon it he discovered the fossil plant, Scolithus linearis, the most ancient organic remains found in Pennsylvania, on which he published a monograph in 1840. During this period he also recorded the observations, real discoveries, that the peregrine falcon makes its nest in