the movement of the auroral display and its correspondence with magnetic movements on the earth; the velocity of the auroral wave; the distribution of auroras over the earth's surface; their occurrence in the Southern Hemisphere; their periodicity; and other points, with the discussion of which the world has since become familiar. In these investigations and in those on other subjects Prof. Loomis was ever intent. Prof. Newton says, upon answering the questions, "What are the laws of Nature? What do the phenomena teach us? "To establish laws which had been already formulated by others, but which still needed confirmation, was to him equally important with the formulation and proof of laws entirely new."
Prof. Loomis was a prolific writer. The list of his books and papers comprises one hundred and sixty-four titles upon every topic of the sciences in which he was especially interested with which he came in contact, recording the results of his experiments and their different stages. What are perhaps his most important papers were the series of Contributions to Meteorology which, beginning in April, 1874, he communicated twice a year to the National Academy of Sciences, and afterward to the American Journal of Science, in which they furnished the leading articles in eighteen volumes. In them were discussed the results of the Signal-Service observations and the subjects of European publications in meteorology. A revision of the papers was begun in 1884, on which he labored for the rest of his life, and was given to the public in three chapters, the third chapter, discussing the theory of storms, appearing in 1889. In connection with his college lectures on meteorology he published a treatise on the subject in 1868, which, "notwithstanding the rapid advances of the science during more than twenty years, is still indispensable to the student of meteorology." He published in 1850 a volume on The Recent Progress of Astronomy, especially in the United States, which went through two editions, and was then rewritten and enlarged. It was followed by the Introduction to Practical Astronomy and by popular articles in periodicals. During his connection with the University of New York he prepared a series of text-books in mathematics. The series comprised nearly twenty volumes on the subjects from arithmetic up, and, being well adapted to the requirements of teachers, has proved highly useful and successful. Not in the line of science, but a work of industry useful and interesting to all concerned, is the Loomis Genealogy, for which he made inquiries on each of his four visits to Europe, and entered into personal correspondence with every family of Loomis in the United States of which he could hear, and which grew till it contained the names of 8,680 descendants in the male and 19,000 in the female line, of Joseph Loomis, the
