ONONDAGA LIMESTONE. 177 



is true, but not to the extent which has been supposed. From a careful collation of facts, 

 I am rather disposed to attibute the high character which the western counties have en- 

 joyed, and do now enjoy, as a wheat-growing district, to the lower part of the Helderberg 

 division. It is here, as I have just pointed out, that the green and red shales, the plaster 

 formation, etc, are situated, and to which, from their peculiar composition and their ready 

 decomposition, we may with greater probability attribute this important feature in the 

 agriculture of these counties. Upon this limestone, however, we invariably find an excel- 

 lent and productive soil, and it is one which this rock has assisted in creating, but it is not, 

 in the eastern or western part of the State, wholly derived from it ; neither has the soil 

 which reposes upon it a greater amount of calcareous matter, than has the soil of the next 

 rock above or below it. It is a mixture composed of drift from a distance, and some de- 

 rived from the green shales. It is not a rock which is very much subject to disintegration, 

 and hence there is not an accumulation of calcareous matter, or an excess of it any where 

 disseminated through the superimposed soil. 



Mr. Hall, in speaking of this rock, remarks, that where it is thin, as in the eastern part 

 of the district, it scarcely produces any effect upon the soil ; but where it is thicker, it has 

 essentially modified its character. Where hornstone prevails, and when the larger masses 

 are removed, the soil, though quite siliceous or abounding in angular fragments of this 

 mineral, is nevertheless always of the best quality. This is supposed to be owing to a 

 constant supply of fresh calcareous matter derived from broken down fragments, which 

 constantly acts as a fertilizer.* This subject will be brought before the reader again, when 

 the peculiar composition of the soil upon this rock will be stated in detail. 



Uses to which the Onondaga limestone is adapted. It is extensively employed for producing 

 lime ; and much that comes to the Albany market is from the Helderberg, and mostly 

 from the inferior part of this rock, or the gray and white portions which are free from 

 shale and hornstone. Where the rock is sound and free from flint or hornstone, it may be, 

 and is to some extent, wrought as a marble : it is gray, and sometimes reddish, and then 

 receives a tolerable polish, and besides it is durable and strong. It is well adapted to 

 works in which a durable material is essential : it is not at all subject to disintegration 

 where the surface is well wrought ; neither is it traversed by fissures that open by frosts, 

 in case the stone is well selected. It is, therefore, one of the most important and useful 

 rocks in the New- York series. 



* Hall's Report, p. 170. 



[Agricultural Report.] 23 



