LITERARY NOTICES. 



559 



perihelion of the comet of 1843 may be not 

 substantial, but merely representative of a 

 state of ether set in a particular undulating 

 motion by the influence of the comet. The 

 origin of comets may be various from solar 

 or planetary explosions ; from explosions in 

 distant stars, or from the scattered matter in 

 space any or all of these. Meteoric stones, 

 meteoric showers, and cosmic dust are con- 

 sidered, and an equal variety of possible ori- 

 gins is supposed for them. The sidereal 

 system comes next under review, in the sev- 

 eral categories of the constellations, the po- 

 sitions of the stars in the sky, their mag- 

 nitude or brightness, the measurement of 

 celestial distances, the light of the stars, 

 changes observed in the heavens, double, 

 multiple, and colored stars, the proper mo- 

 tions of the stars, and the structure of the 

 visible universe. A hopeless effort is made 

 to convey a conception of the magnitude of 

 the universe. We might sail forever through 

 it with the velocity of light, and still be only 

 at the beginning of our journey. The last 

 chapter gives a simple lesson in home as- 

 tronomy a fitting introduction to Mr. Ser- 

 viss's Astronomy with an Opera-Glass. 



The Life and Inventions of Thomas Alva 

 Edison. By W. K. L. Dickson and 

 Antonia Dickson. New York : Thomas 

 G. Crowell & Co. Pp. 3G2. Price, 

 $4.50. 



This biography, the authors claim, has 

 been prepared " under unique facilities for 

 procuring fullness and accuracy of fact, and 

 thence for creating a living and sympathetic 

 picture of the man. The materials have been 

 obtained from the observations of a close 

 business and friendly association of the 

 authors with their subject for a period of 

 thirteen years, and from the verbal and 

 written data which Mr. Edison has most 

 freely and kindly supplied. To this should 

 be added manuscripts from the leading mem- 

 bers of the Edison staff and the inventor's 

 private files of periodicals, covering over 

 thirty years, and embracing the best work 

 of American and transatlantic journalism." 

 Having made careful and discriminating use 

 of this material, the authors believe they 

 have given the first full, accurate, and, to 

 Edison, satisfactory life of the inventor. 

 Besides the matter conventionally appropriate 



to a biography and the accounts of Edison's 

 numerous and valuable inventions, the book 

 abounds in anecdotes, lively sketches, dra- 

 matic passages, and little incidents illustrat- 

 ing the vicissitudes of the subject's career, 

 his peculiar turns of mind, his skill in adap- 

 tation and manipulation of already existing 

 mechanism to give effect to his new ideas, 

 and the ever-consistent bent of his genius. 

 The account of his work with the electric 

 light is varied with the descriptions of the 

 journeys of his agents in South America and 

 Asia in search of the best fiber for lamps, 

 occupying two chapters. There are given 

 us here the stories and descriptions of Edi- 

 son's many experiments and improvements 

 in telegraphy, his vote-recorder, his phono- 

 graph and allied instruments, his work in 

 electric raih'oading, the kinetoscope, and the 

 other applications. The laboratories at 

 Menlo Park and Orange, and the various 

 shops, are noticed in such a way as to give a 

 current view of the development of the elec- 

 tric industry from its modest and doubtful 

 beginnings to its present triumphant pros- 

 perity. The tone of the biography is one 

 of enthusiastic admiration, and the book is 

 profusely illustrated. 



Defective Speech and Deafness. By Lillie 

 Eginton Warren. New York : Edgar 

 S. Werner, 108 East 16th St. Pp. 116. 



This book is written primarily with ref- 

 erence to children, especially in schools, who 

 have a deficient sense of hearing, but whose 

 teachers and even their parents may not be 

 aware of the fact. " Yet the deafness may 

 be serious enough to interfere with progress 

 in their studies. Such children are frequent- 

 ly considered dull and inattentive jiupils. 

 Many suffer from catarrhal affections and 

 thereby present a variability of hearing, 

 which makes them appear to better advan- 

 tage on some days than on others. Thus 

 they add to the teachers diSiculty in distin- 

 guishing them from the willfully disobedient. 

 If one ear is defective and the other not, 

 there will be times when the child hears 

 well, and soon after, having turned his head, 

 he fails to understand and becomes indiffer- 

 ent." The number of children troubled with 

 defects in hearing has been found much 

 larger in the schools of several different 

 countries than any one at first thought would 



