hemisphere. Dr. Gould has just finished at Cordoba a series of like researches, in the course of which he has taken 106,000 observations of southern zones. Almost at the same time he was engaged in a second series of determinations of great precision, involving 110,000 meridian observations between the equator and the south pole. In this work he determines anew all the co-ordinates of the stars observed at different epochs by Lacaille, Piazzi, Brisbane, Rümker, Johnston, Taylor, Maclear, Ellery, and others. He has also made observations of other stars down to the ninth magnitude, which gave him his fundamental positions. By these three great works he has established certain bases for future research. Henceforth the position of all heavenly bodies may be referred to those of well-determined stars, and, by comparing the co-ordinates of his second catalogue with those obtained in the past by Lacaille and others, important conclusions may be arrived at as to the movements of the fixed stars. Dr. Gould has used photographic processes in the determination of star places with great success, and almost all the star-clusters of the southern heavens can be found in the two hundred plates obtained by him, several of these plates containing about two hundred stars each. This latest work is not yet published, but some of the plates obtained the highest prize at the Philadelphia Exposition.
Besides these great astronomical works, Dr. Gould has done much in quite another line, which can merely be mentioned here. The United States Sanitary Commission has published a work by him of 400 quarto pages, containing the results of physiological observations on over 30,000 men from the point of view of statistical anthropology. The same work contains the results of innumerable experiments made in the Federal army upon 1,300,000 men, with a view to determine human growth between the ages of fifteen and fifty.
The climatic conditions of South America were quite unknown in 1872. Dr. Gould has established a net-work of meteorological stations, extending on one side from the tropics to Tierra del Fuego, and on the other from the Andes to the Atlantic. Observations are now made regularly three times a day in twenty-five stations. One volume in quarto has already been published on the climate of Buenos Ayres, and others are being prepared.
On Dr. Gould's first return home for a short visit, a public reception was arranged for him in Boston in response to the following invitation: