their significance, were first carefully observed by Professor Denison Olmsted in 1833, who gave much attention to the question of their nature and origin. But, as Professor C. S. Lyman states in his biography of Professor Olmsted, it was not till thirty years after his and Professor Twining's studies of the subject "that the labors of Professor Newton in this country, and of Professor Adams and others abroad, made it possible to designate the precise orbit of the November stream, and to identify it with that of a comet having a period of thirty-three and one fourth years." The phenomena continued to have diligent observers at New Haven, prominent among whom was Mr. Herrick, the librarian, and afterward, till 1862, the treasurer of the college. At the time of his death, the biographer in the "History of Yale College" records, "Professor Newton was already engaged in organizing combined and methodical observations on shooting-stars, and in collecting and publishing in the 'Journal of Science' the results of independent observers. Under his supervision a map of the heavens was prepared, which was published by the Connecticut Academy, and could be used by observers to mark down the apparent paths of the meteors. A rich harvest of observations was thus obtained by zealous laborers in various parts of the country, many of whom had been interested and trained in the work by Professor Newton. The separation of the precious grains of truth from the chaff—the perception of the constant amid the accidental, of fixed laws disguised by the errors of observations made under circumstances which precluded the use of instruments of precision—is, however, the more difficult part of such investigations. The published results of Professor Newton's studies in this direction are mostly to be found in the 'Journal of Science' and in the 'Memoirs' of the National Academy. The memoir read to this Academy a few years ago is an almost exhaustive discussion of the phenomena exhibited by the sporadic shooting-stars. He has also contributed admirable summaries of what is known in respect to the laws of meteors to the new edition of the "Encyclopædia Britannica" and to "Johnston's Cyclopædia."
"But the investigation which has been followed by the most remarkable results relates to the November meteoroids, and was based upon researches into early records of remarkable star-showers. From such records, Professor Newton showed that the period of revolution of these bodies must have one of five accurately determined values. From the same sources he determined the secular motion of the node of their mean orbit. The five values of the period, with the position of the radiant point, which had also been determined, would give five possible orbits. The real orbit could be distinguished from the others, as Professor Newton remarked, by the calculation of the secular motion of the node due to the disturbing influence of the planets for each of the five orbits. This calculation was subsequently undertaken by Professor Adams, of Cambridge, England, and the real orbit was ap-
