FLEXURE OF ROCK. 



323 



the head and foot of the slab, that near the head being a 

 little distance from the end, for that end is raised slightl}^ 

 above the general level.* 



Fig. 2 shows the deflection from a straight line drawn 

 over the terminal edges of the further side of the slab 

 bearing the name. Fig, 3 shows the same for the nearer 

 side. The maximum deflection is 1.65 inches. The 

 measurements were taken with a finely divided steel rule 

 and tape. 



Minor flexures occur at several places showing an ex- 

 treme sensitiveness of the slab to stress. In this case, 



1^ 



"^^^^^^^^^ 



J!o.2 





^ /M" ?.^" iM" ,p ' 



JTo3. 



* Sketch of grave iu Laurel Hill Cemetery, San Francisco, California, 

 showing deflection of a slab of marble due to its own weight. Dimen- 

 sions of slab 6 ft. 4 in. by 2 ft. 6 in. by | in. Put in place in 1882.(?) 

 Measurements taken December, 1892. 



