12 Mr. Nixon on the Heights of some of the principal 



regularly made in the course of the day at the lowest and 

 highest of the trigonometrical stations within reach, in order 

 to ascertain and correct the error of the measurements by 

 the barometer. When the station at the base could not con^ 

 veniently be revisited, the observation at the superior one, to- 

 gether with their difference of altitude, served to determine the 

 fall or rise of the barometer. 



The following list, comprising the chief beds of the Ingle- 

 ton Fells, is arranged conformably to their order of superposi- 

 tion. 



A 1. Various beds of grits; Yorkshire paving grits (very si- 

 liceous), micaceous sandstones (flagstones and roofing 

 slates) with beds of shale, bearing on some hills three 

 seams of coal. 

 2. Very rough millstone grit (240 feet thick on Pen-y-gent). 



B. The top lime of the Ingleton Fells and the upper part 



of Wharfdale. It is of very variable thickness, and 

 contains lead in Dod and Settron Fells. 



C. 1. A thick bed of various shales with grits and flagstone 



beds interstratified. It contains a seam of coal on 

 Noughtberry hill at the Garsdale, King's-cross, and 

 pits. 



2. Various beds of paving grits, flagstone beds, and shales. 



In the lower half of this section are two or three very 

 thin beds of limestone. 



3. Yorkshire paving grit and shale. 



D. 1. Limestone shale containing beds of Dent black marble. 



2. Gray limestone without shale, &c. Lead has been found 



in this bed south-west of the summit of Ingleborough, 

 and is at present procured on the north-west side of 

 the hill. 



3. (In some places) a very thin bed of clayshale containing 



a slender seam of coal. 



E. Grauwacke, (clayslate, &c?) 



Heights of different points of these sections, ninth their bearings 

 and distances from the summit of Ingleborough. 



A. 1 & 2. Height of the station on the loftiest point of Ingle- 



borough, 2374 feet above the Irish Sea. 



B. Height of the upper surface of the top lime on the sum- 



mit of Simon Fell (part of Ingleborough) one mile 

 E.N.E., 2125 feet 



C. 1. Height of the under surface of the top lime (at a spring) 



half mile E.S.E., 2062 feet; — (at a spring dividing 

 Simon Fell from Ingleborough) half mile E.N.E., 

 2061 feet;— (on Simon Fell) li mile E.N. E., 2035 



feet. 



