POPULAR SCIENCE MONTHLY.
latter are described in a chapter by G. Brown Goode. The Bureau of American Ethnology, one of the most efficient of the Government's scientific departments, is treated of by W J McGee. Several other papers calling attention to various outside scientific enterprises instituted by the Smithsonian, the international exchange system, the National Zoölogical Park, etc., are concluded by an appreciative sketch of G. Brown Goode by David Starr Jordan; and finally we have a series of papers under the heading. Appreciations of the Work of the Smithsonian Institution, which occupy the last three hundred pages. A number of excellently executed portraits add much to the attractiveness of the volume, which is in purpose, contents, and mechanical execution a worthy monument to the institution which it describes.
By the Sun's Place in Nature Sir Norman Lockyer means the stage of stellar evolution through which the sun is passing. This subject and the constitution of the sun, the source of its light and heat, and the nature and history of meteorites, stars, and nebulae, as they may throw light upon what is going on in the sun, have been the objects of Professor Lockyer's studies for a long period. The results of twenty-five years' investigation of the subject and the conclusions the author had matured have been published in the books The Chemistry of the Sun and The Meteoric Hypothesis. Their most important points were, as regards the general question, that there is the closest possible connection between nebulæ and stars, they representing two stages in an evolutionary series: that the first or nebulous stage in the development of cosmical bodies is not a mass of hot gas, but a swarm of cold meteorites; that some of the heavenly bodies must be increasing their temperature, while others are decreasing; and that therefore a new classification is demanded, based on the varying states of condensation of the meteoric swarms. Great advances have been made in physical astronomy since these books were published. Larger telescopes have been in operation; the system of mountain observations has been established and carried on; spectroscopic observations and astronomical photography have been energetically prosecuted; novæ or new stars have come and gone; and the mysterious element, helium, of the solar spectrum, has been found on the earth. A new discussion seems to be required in view of these recent developments, and is given in the present work. Vogel's classification of stars based upon the supposition that all the stars are cooling is set by the side of the author's view in the face of the new evidence, and the conclusion is reached that the result of the test is in favor of the latter; that some stellar bodies are increasing their temperature, while others are reducing it; that the sun is cooling in a similar stage with that of Arcturus and Capella; that the theory that the primal nebula of the sun was not exclusively gaseous, but only contained gases among its constituents; and also that in general, "along all lines, the fundamental requirements of the meteoric hypothesis have been strengthened by the later work."
Professor Curtis's Text-Book of General Botany is intended as an introduction to the study of the science, and not as a substitute for any of the books designed for persons who would know something of botany and have but little time at their disposal. The text is based upon the laboratory work required of beginners at Columbia University. The book being intended for a single year's work, rigid compression and broad generalization have been compelled. The author emphasizes the importance of guarding the student "against the peril of making him dependent upon directions and so defeating one aim of the work, the making of self-reliant, intelligent observers. The student should see everything, but first and clearly
- The Sun's Place in Nature. By Sir Norman Lockyer. New York: The Macmillan Company. Pp. 300. Price, $2 75.
- A Text-Book of General Botany. By Carlton C. Curtis. New York: Longmans, Green & Co. Pp. 359. Price, $3.