ACKNOWLEDGMENTS OF ILLUSTRATIONS 



Yerkes Observatory Fig. 1. M. C. Ford, Bowling Green, Ky. 

 Figs. 4, 34 and 199. The Macmillan Company Figs. 13 and 43. 

 L. W. Brown, Photographer, U. W. Fig. 30 and frontispiece. 

 American Chemical Company, Boston Figs. 32, 142 and 169. 

 Janesville Machine Company, Janesville,Wis. Figs. 66, 68, 69, 71, 

 74, 85, 87, 92, 106, 107, 112, 143, 210 and 213. Deere and Company, 

 Moline, 111. Figs. 73 and 88. Moline Plow Company, Moline, 

 111. Fig. 160. D. S. Bullock, U. W. Fig. 144. Allis-Chalmers 

 Mfg. Co., Milwaukee Fig. 155. Rockfield Products Company, 

 Milwaukee Fig. 154. Jeffrey Mfg. Company, Columbus, Ohio 

 Fig. 157. J. S. Donald, Mt. Horeb, Wis. Fig. 159. Mark W. Potter, 

 Belhaven, N. C. Figs. 195, 196 and 204. Mosier and Gustafson, 

 authors of Soil Physics and Management Figs. 18, 64, 67, 80, 

 93, 98. John W. Lloyd, author Productive Vegetable Garden- 

 ing Fig. 95. Kary C. Davis, author Productive Plant Hus- 

 bandryFig. 93. U. S. Dept. of Agriculture Figs. 170 to 

 187, inclusive. 



