"_Stars and Telescopes_,"[23] Professor _Todd_ says, "is intended to meet an American demand for a plain, unrhetorical statement of the astronomy of to-day." We might state the purpose to be to bring astronomy and all that pertains to it up to date. It is hard to do this, for the author has been obliged to put what was then the latest discovery, made while the book was going through the press, in a footnote at the end of the preface. The information embodied in the volume is comprehensive, and is conveyed in a very intelligible style. The treatise begins with a running commentary or historical outline of astronomical discovery, with a rigid exclusion of all detail. The account of the earth and moon is followed by chapters on the Calendar and the Astronomical Relations of Light. The other members of the solar system are described and their relations reviewed, and then the comets and the stars. Closely associated with these subjects are the men who have contributed to knowledge respecting them, and consequently the names of the great discoverers and others who have helped in the advancement of astronomy are introduced in immediate connection with their work, in brief sketches and often with their portraits. Much importance is attributed by Professor Todd to the instruments with which astronomical discovery is carried on, and the book may be said to culminate in an account of the famous instruments, their construction, mounting, and use. The devisers of these instruments are entitled to more credit than the unthinking are always inclined to give them, for the value of an observation depends on the accuracy of the instrument as well as on the skill of the observer, and the skill which makes the instrument accurate is not to be underrated. So the makers of the instruments are given their place. Then the recent and improved processes have to be considered, and, altogether, Professor Todd has found material for a full and somewhat novel book, and has used it to good advantage. [23] Stars and Telescopes A Handbook of Popular Astronomy. Boston: Little, Brown & Co. Pp. 419. Price, $2. _Some Observations on the Fundamental Principles of Nature_ is the title of an essay by _Henry Witt_, which, though very brief, takes the world of matter, mind, and society within its scope. One of the features of the treatment is that instead of the present theory of an order of things resulting from the condensation of more rarefied matter, one of the organization of converging waves of infinitesimal atoms filling all space is substituted. With this point prominently in view, the various factors and properties of the material universe--biology, psychology, sociology, ethics, and the future--are treated of.