281 



The length of the perpendicular from the toe of the face 

 to the top, or top produced, is represented by h\ ; and the 

 length of the face itself by h. 



will- is multiplied by the coefficients in Columns 4 to 11 

 inclusive, to find the resistances ; and wh? by the coefficients 

 in Columns 11 and 12. 



Table of Coefficients for finding the maximum Values of the 

 Resistances for different Angles of Repose ; also the Coef- 

 ficients for finding the ultimate Values of the Resistances 

 when the Face is vertical, and Scarp at the natural Slope. 



The slopes marked thus * arc approximate. 



In the preceding equations we have only considered the 

 m9.\\m\xmretaining-forces. The mxmmnm over coming-forces, 

 and the position of the corresponding fractures, are determined 

 in a similar manner, and by similar equations. Retaining the 



