INGLEBOROUGH CAVE. 35 



"The Jockey Cap is 9 feet 10 inches in circumference at the 

 base ; the height is 1 foot 9 inches. Measuring from the lowest 

 side, it is 2 feet 8 inches in height. Water continues dropping 

 upon it from the roof; in the centre is a hole into which the 

 water continually falls, and overflowing its sides is unceasingly 

 at work in increasing the stalagmitic accumulation. 30 Oct. 

 1845. We measured again the Jockey Cap, and found it at the 

 base 10 feet, showing an increase of 2 inches (if our measure- 

 ments are correct, but it is not easy to be accurate). 



" The height from the lowest side is 2 feet 1 1 inches, being a 

 growth of 3 inches. We also measured from the junction of the 

 stalactite at the roof from which the water drops into the top of 

 the Jockey Cap to the rim of the cup or hole into which it falls, 

 7 feet 1^ inch, and the stalactite, from the roof to its lowest 

 point, 10 inches." 



On these data we find that in six years the stalagmitic crust 

 has been increased in height about 3 inches, or about T ^th of 

 the whole ; and in diameter 2 inches, or about g^th of the whole. 

 These experiments will probably be continued. 



But the formation of such stalagmite is only the last part of 

 the process ; the excavation of the cave is an earlier work ; and 

 earlier than the excavation of the cave is the shaping of the lime- 

 stone valley into which it discharges the water, which had fallen 

 in the state of rain and snow on the sides of Ingleborough. 



Ingleborough has attractions for the geologist of no ordinary 

 kind. To reach the summit from Ingleton Beck we pass over 

 four groups of rocks, each full of interest ; and these rocks are 

 cut off toward the south by one of the most magnificent dislo- 

 cations in England, the Craven Fault. For the effect of this 

 fault is to throw down to the south, as much as three thousand 

 feet, the strata of Ingleborough, so as to bury its highest rock 

 below the thick group of coal-measures which are worked below 

 Ingleton. The lowest of the four groups of rocks is the slate 

 rock worked in large quarries in the valley above Ingleton ; the 

 vertical cleavage planes of this slate appear in singular contrast 



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