Jan. 28, 191S 



Study of Plow Bottoms 



155 



SKeleton. Hyperboloid of One Sheet 

 Fig. 3. 



Section z=o. Fig 3. 

 Fig. 4. 



Section y=o, Fig. 3. 

 Fio. s. 



o y 



Section K'O, Fig 3 



Fig. 6. 



Hyperboloid of One Sheet, showing Lines 

 upon the Sorfoce 



Pio. 7. 



