=A Library of Astronomical Photographs.=--The appointment of Mrs. M. P. Fleming as curator of astronomical photographs in the Harvard Observatory is noteworthy because hers is the first woman's name to be placed along with the officers in the university catalogue. It is more so as a recognition of Mrs. Fleming's proved abilities in certain lines of astronomical work. The astrophotographic building is not used for the taking of photographs, but as a peculiar kind of library where the plates secured by the astronomers at Cambridge and Arequipa are preserved, arranged, and catalogued, as is done with books. The duties of the curator are like those of a librarian. But instead of books, of which many copies exist, each of the treasures in the photographic collection is unique and can not be duplicated. Prints of them on paper are of little scientific value, because no paper copy can repeat all the minute accuracy of the original negative on glass; and prints are not taken from them for scientific use, but only for illustration. If one is destroyed it can never be replaced; and it is impossible to predict what fact one of them may embody of the greatest importance to the labors of some future astronomer desiring to compare the aspect of his special object of research at his period and ours. Mrs. Fleming's name is frequently mentioned in the reports of the observatory, and she has distinguished herself in several lines of stellar investigation. She has about a dozen women assistants, some of whom are computors of long experience, and some are known by the discoveries they have made. =Forest Planting on the Plains.=--Mr. Charles A. Keffer, in a report to the Forestry Division on Experimental Tree Planting in the Plains, defines the forestless region of America as including all the States between the Mississippi River north of the Ozark Mountains and eastern Texas and the Rocky Mountains, together with the plateau west of the Rocky Mountains. The possibilities of forest growth in this vast area are yet to be proved. Roughly speaking, any species that thrive in the adjacent wooded region can be grown in Iowa, the Red River Valley of Minnesota and North Dakota, the Sioux Valley of South Dakota and the eastern counties of Nebraska, and in the more southern States. We know that difficulties of cultivation increase as one goes westward, but we can not say where the western limit of successful tree culture is. We can not even define the limits of successful agriculture in the plains, for with increased facilities for irrigation splendid crops are now produced where only a few years ago it was thought desert conditions would forever prevail. It is admitted that forest planting, as a financial investment, will probably be profitable on the plains only in a limited degree. Favorable sites may enable the profitable raising of fence posts and other specialized tree crops, but the growing of timber on a commercial scale can hardly be expected.