116 Kepoet of the State Gteologist. 



stances mentioned in the ]^ew York law regarding fertilizers. It 

 appears that the plaster jper se no longer exercises the beneficial 

 influence upon the soil that it formerly did ; its function being to 

 liberate potash from combinations, its application for a number 

 of times exhausts the capacity of the soil for yielding its potash, 

 and the beneficial effect is no longer observed. 



Road Metal. 



From a strictly practical point of view Geology offers no 

 results of more immediate concern than those bearing on the ques- 

 tion of road building. Attention has been constantly directed to 

 this point in the course of these investigations. A large part 

 of the county, even in the elevated tracts, has a clayey soil, on 

 which the attempt to make good roads has proved a failure. 



It must be confessed that the true principles of road- making are 

 seldom if at all followed. It is well known that deep side ditches, 

 culverts for prompt discharge of side water, under-drainage and 

 arching of the roadbed, are at the basis of all success in road 

 construction ; but in practice they are quite neglected. One 

 seldom sees a properly made dirt road ; and good road metal is 

 commonly wasted by laying it on a poor basis, and by neglecting 

 to crush to size. 



The best road metal is trap, granite and the like, which are out 

 of the question for country roads here. 



Gravel is rather a rare product in this district. Lake gravel is 

 usually shale worn round, and is then little better than shale. It 

 is here suggested that river gravel can be found in considerable 

 quantities in some of the ravines, some of which may prove suit- 

 able for roads. 



The country north of Seneca river has no rock, not even shale. 

 That on the south has at least two belts of limestone, much shale 

 and at the south sandstone. 



The application of the well-known black shale to the roads has 

 a good effect for a time, but the material eventually becomes 

 reduced to its original element, mud. I have known a fine 

 road kept in good order by frequent coats of common Hamilton 

 shale (Moscow shale) applied until a great thickness was accumu- 

 lated ; this was at Kidder's Ferry, where no heavy produce teams 

 pass. In general this material may safely be recommended for 



