ACKNOWLEDGMENTS 



The authors of this book are indebted first of all to 

 the scores of progressive educators who have built 

 up and refined the course in general science and to the 

 pupils of classes in which parts of the manuscript have 

 been used in experimental form. Valuable suggestions 

 have come from Mr. John Groh, critic teacher of gen- 

 eral science at the State Teachers College, East 

 Stroudsburg, Pennsylvania, who used some of the 

 material with ninth grade classes, from Mr. James 

 Gordon Manzer, instructor in science at the Senior 

 High School at Tenafly, New Jersey, and from Dr. 

 Charles K. Sibley of the John Burroughs School, who 

 read and criticised the manuscript and proofs, and 

 from Miss Delia C. Wilson, head of the Geography 

 Department, East Stroudsburg State Teachers Col- 

 lege, who criticised a part of the manuscript. 



Among the individuals and organizations that have 

 made possible the illustrations of the book, the au- 

 thors wish to acknowledge their obligation to the 

 following: Taylor Instrument Company; Paul's 

 Photos ; McGraw-Hill Book Company ; U. S. Weath- 

 er Bureau ; International News Photos ; Underwood 

 and Underwood ; St. Louis Department of Public 

 Utility; Central Scientific Company; Heine Boiler 

 Company; New York City Board of Water Supply; 

 Department of Water of Los Angeles ; U. S. Bureau 

 of Home Economics ; Ruth Cunliff Russell ; Ameri- 

 can Medical Association ; P. Blakiston's Son and 

 Company ; Science Service ; C. K. Sibley ; Lightolier 

 Company ; Eastman Kodak Company ; Bausch and 

 Lomb Optical Company ; General Electric Company ; 

 American Museum of Natural History; National Re- 

 search Council; St. Louis County Gas Company; 



Shell Petroleum Corporation ; American Petroleum 

 Institute; Fisher Scientific Company; Minneapolis- 

 Honeywell Regulator Company ; Keystone View 

 Company ; Foamite-Childs Corporation ; Timken 

 Roller Bearing Company; Chrysler Corporation; Bu- 

 reau of Standards of the Department of Commerce ; 

 U. S. Hoffman Machinery Corporation ; DeLaval 

 Separator Company ; William Thompson ; Hoover, 

 Owens, Rentschler; Busch-Sulzer Bros.; Smithsoni- 

 an Institution ; Union Electric Light and Power Com- 

 pany; Mount Wilson Observatory; Lick Observa- 

 tory; Corning Glass Works; The Macmillan Com- 

 pany ; Yerkes Observatory ; Popular Mechanics Mag- 

 azine ; Popular Science Monthly ; U. S. Forest Serv- 

 ice ; U. S. Bureau of Plant Industry; School of Medi- 

 cine, Washington University; U. S. Bureau of Public 

 Health Service ; Ginn and Company ; U. S. Depart- 

 ment of Agriculture; California Fruit Growers Ex- 

 change; U. S. Bureau of Entomology and Plant Quar- 

 antine; General Biological Supply House; Ohio Elec- 

 tric Manufacturing Company ; National Carbon Com- 

 pany; D. Appleton-Century Company; The Western 

 Union Telegraph Company ; Bell Telephone Labora- 

 tories ; Radio Station KMOX ; Portland Cement As- 

 sociation ; Standard Oil Company of New York; 

 Studebaker Sales Corporation ; Greyhound Manage- 

 ment Company; Baltimore and Ohio Railway; New 

 York Central Railway; Burlington Route; The Pull- 

 man Company; Baldwin Locomotive Works; The 

 Milwaukee Road ; Sperry Gyroscope Company ; In- 

 ternational Newsreel ; Goodyear Tire and Rubber 

 Company ; Bureau of Air Commerce, U. S. Department 

 of Commerce; and Robert P. Osbourn. 



Copyright 1933, 1936, by WEBSTER PUBLISHING COMPANY. No part of this book 

 may be reproduced in any form without permission in writing from the publisher. 



