Page:Popular Science Monthly Volume 3.djvu/520

504 As a teacher he was laborious and enthusiastic, and his success was remarkable. He secured the respect and love of his pupils to a degree seldom equalled; but he was also a zealous student in science, and published several valuable works as the results of his researches. Among these are his "Analytical Geometry," and his "Conic Sections," which, at one time, were extensively used as text-books in our colleges. While connected with the Fellenberg Institution, he published two works on book-keeping, that were adopted by the State schools of Massachusetts. He read many valuable papers before the American Association for the Advancement of Science, of which he was, from its organization, a member; and also before the National Academy of Science, for the recent meeting of which he had in preparation an article on the Storm-curve, the object being to show that it was an hyperboloid, the equation of which he had computed.

His chief reputation, in science, was achieved by his researches in the department of meteorology. These were commenced in 1839, while Principal of the Ogdensburg (N. Y.) Academy. He took simultaneous and constant observations of the barometric changes connected with the variations of the wind-vane and with the fall of rain. His instruments were self-registering. Each motion of the vane directed a minute but constant stream of dry sand into some one of 32 stationary hoppers, corresponding in position to as many points of compass. The weight of sand found in the several receptacles below each hopper showed the length of time that the vane had pointed in that direction. The rain-gauge was an inverted cone, having an horizontal surface of 172.8 square inches: the rain falling into it passed down, through an orifice so small that no appreciable evaporation could occur, into a close-fitting can. One inch of rain in depth would, therefore, make $1/10$ of a cubic foot when collected, the weight of which is 100 ounces. Each ounce that the can contained after a storm, consequently, represented $1/100$ of an inch in perpendicular fall. The amount necessary to merely moisten the funnel without precipitation into the can is easily determined as a constant. The results of these observations for the year 1838 were published by Prof. Coffin in the Meteorological Register, a monthly journal, of which he issued the first number in January, 1839. It was devoted to the discussion of various phenomena connected with physical science. Though the demand for a periodical of this nature was insufficient to sustain it, it brought into correspondence many who were interested in such subjects. The investigation of rainfall and evaporation had present practical value in being made the basis of the report of the committee of the New York Senate, in 1839-'40, appointed to consider the enlargement of the canal system of the State by the construction of the Genesee Valley Canal. These studies were afterward extended to form the chapter on the climate of the State, published in the "Natural History of New York," in 1845, in which the inquiries took a wider range; and questions of