132 



THE POPULAR SCIENCE MONTHLY. 



local trade, the constitution of the village and 

 its development by the organization and di- 

 vision of industries, the establishment of com- 

 munications, the formation of various social 

 groups, and all the processes of commercial 

 and municipal growth into the town and the 

 city. The third book concerns social anat- 

 omy and the analysis of the elements and 

 factors in the development described in the 

 preceding book ; the fourth book, the physi- 

 ology and pathology of society ; and the fifth 

 book, its psychology. The essay is illustrated 

 by five maps and charts delineating the sev- 

 eral stages of the growth of the social organi- 

 zation. 



Progress in Flying Machines. By 0. Cha- 

 NUTE, C. E. The American Engineer and 

 Railroad Journal, 47 Cedar Street, New 

 York. Pp. 308. Price, $2.50. 



The subject of aerial navigation has be- 

 come quite prominent of late by reason of 

 important advances in this field that have 

 been made during the past few years. The 

 idea of controlling the course of a great bag 

 of gas through the currents of the atmos- 

 phere has been well-nigh abandoned, and 

 reliance is being placed more and more upon 

 mechanical motors, the buoyancy of the air 

 as exerted under large horizontal surfaces, 

 and the force of the wind. Flying machines 

 are now deemed much more practicable than 

 dirigi))le balloons. Mr. Chanute's book con- 

 sists of a scries of illustrated articles contrib- 

 uted to The Railroad and Engineering Jour- 

 nal, the chief aims of which were to show 

 whether or not man-flight is possible ; to save 

 waste of effort on the part of experimenters 

 by making known what forms of apparatus 

 have failed ; and to enable investigators to 

 judge as to whether new machines that may 

 be proposed in future are worthy of trial. 

 The author divides flying machines into three 

 classes : (a) Wings and parachutes ; {h) screws 

 to lift and propel ; (c) aeroplanes. Flapping 

 wings in imitation of those of birds were 

 eariy tried, and Mr. Chaaute describes many 

 curious forms of them, the earliest authen- 

 ticated proposal being credited to Leonardo 

 da Vinci. The first known proposal for an 

 aiirial screw was also his. Aeroplanes, how- 

 ever, do not date back much before the mid- 

 dle of the present century. Like the first- 

 mentioned class of machmes, their principle 



is derived from an action of birds in this 

 case the soaring or sailing action. Most of 

 the flying machines described are shown in 

 simple drawings. The results attained by 

 Maxim, Lilienthal, and other recent expeii- 

 menters are given, the book having been held 

 back from the binder to append Lilienthal's 

 own account of his latest work. 



Six General Laws of Nature (a Ne^o 

 Idealism) is a compendium, by Solomon J. 

 Silberstein, of a large work which he con- 

 templates publishing, on Divinity and the 

 Cosmos. It is intended to contain " the 

 primitive cause of force and matter, an ex- 

 planation of all the physical phenomena in 

 the actuality of the universe, and an attack 

 on the modern scientists and philosophers." 

 The author has satisfied himself by careful 

 analysis that all the systems of philosophy 

 are incomplete, unsatisfactory, and insuffi- 

 cient to the deep, logical, and honest thinker, 

 and that most of the laws or axioms in mod- 

 ern natural science are very often defective, 

 and even false. He therefore issues this 

 work in correction of these errors, with the 

 arguments and demonstrations through which 

 he believes he has discovered the mystery 

 and explained the physical phenomena of 

 Nature. 



The fields of biology and physics meet 

 in the Investiffations on Microscopic Foams 

 and on Protoplasm., by Prof. 0. Biitschli, of 

 Heidelberg, which has recently appeared in 

 an English translation (A. & C. Black, Lon- 

 don, $6.25). Protoplasm is conceived of in 

 this work as having the structure of a froth 

 or foam in which minute droplets of a watery 

 liquid take the place of air in the bubbles of 

 an ordinary foam. The author has carefully 

 investigated this structure in an effort to 

 throw light upon the physical conditions of 

 the phenomena of life. He has imitated it 

 in oil foams and studied the phenomena of 

 these, and has also investigated the structure 

 of protoplasm in various organisms. About 

 half the work is devoted to a summary of 

 the views of other investigators upon the 

 structure of protoplasm. The volume con- 

 tains a list of works referred to, an index, 

 twelve lithographic plates, and a number of 

 figures in the text. 



In preparing a series of essays on TTie de- 

 lation of Biology to Geological Investigation 



