STRATIGRAPHICAL ORDER. 83 
age, and, like it also, it has a very slow descent, the average fall having 
been found to be not more than 1 foot to the mile. 
We have already recovered the section that we left on the Tus- 
carawas side of the divide, in its integrity. The Putnam Hill lime- 
stone is the base of the new section, and the Upper Freeport coal its 
summit. The limestone is found near the lowest level of the valleys. 
Its last occurrence is one mile above Kimbolton (Liberty), on the 
J.S. Frame farm, section 24, Liberty, where it has been quarried and 
burned for lime in past years. Its coal is below it here, but it is thin 
and worthless. 
The Lower Kittanning coal takes its place again in some of the 
sections, and the interval between the Putnam Hill limestone and the 
Middle Kittanning coal is somewhat increased. The Kittanning clay 
is also well shown beneath the Lower coal. As to the Middle Kittan- 
ning coal, everybody knows its place and its character. It has been 
opened and worked on every farm without exception for a number of | 
miles in the main valley. 
The section which begins at Kimbolton with the Putnam Hill 
limestone can be carried, in the high ridge that lies south of the town, 
(the New Salem Ridge), up to the Cambridge limestone. This is a new 
element, but one that will be found almost indispensable to our safe 
advance to the southward. The Kimbolton section becomes very 
valuable by reason of the fact that it embraces these two characteristic 
elements. It is shown in the accompanying diagram, Fig. XVI: 
The Lower Freeport coal and the Kittanning clay were both found 
in a shaft sunk by Hon. T. S. Luccock near his residence. 
The upper portion of the section was measured in the Salem road, 
southeast from Kimbolton, beginning with the Middle Kittanning coal, 
as opened on the James Gibson farm, section 22, Liberty. The Cam- 
bridge limestone occurs almost everywhere along the Salem ridge, sec- 
tion 1, Liberty, extending as far as the Henry McCartney farm to the 
eastward, and southward to Cambridge with but few interruptions. It 
was mistaken by Stevenson in this part of the county for the Crinoidal 
limestone, which it resembles in some of its phases. The Crinoidal 
limestone belongs fully 100 feet higher in the scale. 
The Gibson coal, which makes the base of the upper section, is 
below the level of high water of Will’s Creek. The seam can be fol- 
lowed to the south line of Liberty township, where it goes under the 
