disease among chinch-bugs. Another useful paper, by George E. Curtis, shows the utter untrustworthiness of the weather predictions, made for a year ahead, by a local weather prophet. Some other topics treated are Artesian Wells in Kansas, Cements manufactured in Kansas, Notes on Gophers, and the Manufacture of Binding-twine.
A service has been done to persons interested in forestry by the publication of Insects injurious to Forest and Shade Trees, by Prof. Alpheus S. Packard, being the fifth report of the IT. S. Entomological Commission (Department of Agriculture, Washington). The volume has 957 pages, and its contents are arranged under the names of trees. The body of the work is introduced by a chapter of general information, which includes descriptions of various insecticides, and of mean3 for applying them to trees. The text is illustrated with 306 cuts and 40 plates, some of the latter being colored. There are separate indexes of insects, of plants, and of authors quoted.
A sketch of what has been done toward inventing a practical air-ship is given in the lecture on Aerial Navigation, by O. Chanute, C. E., reprinted from The Railroad and Engineering Journal as a pamphlet. Mr. Chanute sketches the progress in ballooning since the time of Montgolfier, and describes also the attempts that have been made to construct mechanical flying machines. He believes that dirigible balloons, which have already attained a speed of fourteen miles an hour, will before long be driven at the rate of twenty-five to thirty miles, and says that much greater speeds may, perhaps, be attained eventually with aëroplanes.
Bulletin No. 19 of the U. S. Coast and Geodetic Survey is a report by Ensign J. C. Drake on The Sounds and Estuaries of Georgia, with reference to oyster culture. It embodies an examination of all the waters under the jurisdiction of the State of Georgia in which oysters grow naturally, or in which they probably could be made to grow. The extent of each body of water is given, the character of its currents and its bottom, the area of any existing oyster-beds in it, and the density of the water. Seven large folded charts accompany the text.
The Zoölogical Articles contributed to the Encyclopædia Britannica by E. Ray Lankester have been reprinted in a volume with kindred articles by eminent specialists, which are also taken from the Encyclopædia (Scribners, $5). Dr. Lankester states, in the preface, that the purpose of the volume is to make these monographs readily accessible to university students. His own articles are those on protozoa, hydrozoa, mollusca, polyzoa, and vertebrata; the others are, Sponges, by Prof. Sollas; Planarians, by Prof, von Graff; Nemcrtines, by Prof. Habrecht; Rotif era, by Prof. Bourne; and Tunicata, by Prof. Herdman. These together form a treatise on a considerable section of the animal kingdom. In the reprint a few errors have been corrected, and some notes and illustrations have been added.
The Transactions of the Iowa State Medical Society, for 1890, contains the proceedings of the thirty-eighth annual session of the society, held in April, 1890, and a large number of papers presented at that meeting, with the discussions upon them. A subject of popular interest, treated in one of these papers, is pension examinations, the burden of the paper being a complaint that examining surgeons are required to perform several hours of professional labor for one or two dollars. The address of the president was on the question, Should persons who have inherited disease detrimental to society and the State be allowed to marry? the negative side being taken.
Johnson's comprehensive treatise on Surveying (Wiley), first published in 1886, has reached its seventh edition. Some changes have been made each time a new edition has appeared, and this issue contains a great many. To the part on surveying instruments have been added descriptions and cuts of the architect's level and several other instruments; the table of magnetic declination formulæ has been replaced with the new table of the U. S. Coast and Geodetic Survey; the isogonic chart of the United States has been redrawn and brought down to 1890; the chapter on land-surveying has been recast, and considerable new matter concerning monuments and the rules governing the resurvey of lands has been added; the description of the U. S. Land Surveys has been rewritten and expanded; a method of running out parallels of latitude, with suit-
