"SLIDES" IN THE CONEMAUGH FORMATION 



353 



ing caused by upslope slides, sometimes by caving, the result of 

 downslope slides. The most obvious remedy for the former is to 

 reduce the slope by cutting away on the uphill side, and to produce 

 the same result by filling in on the lower side. On the new slopes 

 so made the growth of vegetation should be encouraged. It might 

 prove practicable in extreme cases to prevent saturation of the 

 trouble-making shale by well-planned drainage. Heavy retaining 



Fig. 5.— Slides have undermined the brick-paved road at this point. The line 

 of dirt through the center of the road fills a crack and reduces the gradient between 

 the sides of the offset. At the far end marked by the position of the man, half the 

 road has dropped to such an extent as to require blocking off. 



walls should be successful in some instances. These remedies may 

 be considered appHcable only in extreme cases, or with such portions 

 of the road where the trouble is due to the cut made in grading. 

 The total avoidance of damage would mean a cost in preventive 

 arrangements greater than the total of prospective damage. 



Electric railroads are subject to the same conditions as the 

 highways. The steam railroads in the immediate vicinity of 



