PREFACE Vli 



pupils rather than in the principles and laws of any branch 

 of science. And it has been the aim to select as material 

 for study not only that which is valuable in itself but that 

 which at the same time is likely to be a stimulus in a truly 

 educative process. 



The author wishes to express his appreciation of the 

 helpful suggestions and criticisms coming from those who 

 have read the manuscript of these lessons. He desires 

 especially to thank Professor George E. Martin, Head of 

 the Department of English in the State Normal School at 

 Kearney ; and Dr. R. J. Pool, Professor of Botany in the 

 State University at Lincoln. He is greatly indebted, too, 

 for helpful suggestions from the following who have read 

 portions of the manuscript : Miss Alice Loomis, Head of 

 the Department of Home Economics at the State Univer- 

 sity of Nebraska ; George E. Loveland, Professor of 

 Meteorology in the State University and Director of the 

 U. S. Weather Bureau ; Dean E. L. Rouse, Superintend- 

 ent of Practice in the State Normal School at Peru ; 

 Professor H. C. Filley, Head of the Department of Farm 

 Management in the College of Agriculture ; and Professor 

 B. C. Hendricks of the Department of Physics in the 

 State Normal School at Peru. 



HERBERT BROWNELL. 



LINCOLN, NEBRASKA. 

 1916. 



