THE American Meteorological Journal for May contains the following articles:—Cold waves, by Prof. T. Russell. In the report of the Chief Signal Officer for 1889, he expressed the view that the origin of cold waves was due to mixture of upper and lower air causing cooling of the layer next to the ground. On further examination of the subject, in connection with the observations at mountain stations, he admits the incorrectness of those views, and states that, while it is essential to connect the low temperature and high pressure in some way, the cooling of the ground by radiation, and of the air by contact and conduction, will not completely explain the cause of cold waves.—How could the Weather Service best promote agriculture?, by M. W. Harrington. The American Weather Service has hitherto devoted itself more particularly to the interests of commerce, while the State Services have had the interests of farmers more distinctly in view. What the farmer wants to know is, where and when a local shower will fall. While the complete solution of this problem may be impossible, the approximate solution lies in the multiplication of local forecasting stations, and in the intelligent use of the indications of the Central Office, combined with the indications which he can himself observe. The author recommends more attention to climatology as distinct from weather changes, and to the relations between plants, soil, and meteorology.—Is the influenza spread by the wind?, by H. H. Hildebrandsson. This is a translation, by the author, from an article in the Journal of the Medical Society at Upsala, and is, practically, a reply to an article in NATURE of December 19, 1889, where it is stated that the malady is probably spread by the wind. The author shows, by a map and table, the places and dates at which influenza occurred in Sweden, from inquiries of medical men. The result of the research goes to show that the influenza is propagated by infection, that it is conducted from place to place through human circulation, and that the time of incubation is two to three days. The state of the weather seemed to have no influence on the spread of the malady; in fact, it raged with the same severity in countries possessing very different climates, and during very different weather conditions.