﻿44 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN [Feb. I905, 



by Messrs. Shaw & Lovegrove to prevent their loss. The foreman, 

 Mr. George Walton, rendered us very great help, and so far as 

 possible arranged the work of the men under him to suit our 

 requirements. Messrs. Shaw & Lovegrove also provided quarrymen 

 and labourers to carry on the excavations, which were paid for from 

 funds collected mainly from Derby, Buxton, Bakewell, and Matlock. 

 The excavating-work was for the most part carried out under the 

 direction and supervision of one of us ; but Mr. Storrs Eox, of 

 Bakewell, visited the cavern a number of times in 1902, and on 

 several occasions superintended the work. 



In July 1902, we decided to suspend operations until the quarry- 

 face had been worked farther back, parallel to the length of the 

 cavern, in order that the deposits might be worked at a lower level 

 than that of the line AB in the horizontal section (PI. V, fig. 1). 



II. The present Physical Conditions or the District, and a 



D ESCRIPTION OF THE QUARRY. 



The Hoe-Grange Quarry (6-inch Ordnance-Survey map, xxxm 

 S.E. ; 1-inch Geological-Survey map, 72 N.E.) is close to the 

 High Peak Railway, about a quarter of a mile north-west of 

 Longcline Station (which is on the road from Matlock to Ash- 

 bourne) and a little more than a mile north-west of the village 

 of Brassington. It is situate on the south-eastern portion of the 

 Mountain-Limestone plateau, which extends from near Wirksworth 

 on the south-east to Buxton on the north-west, at a height varying 

 from 1000 to 1200 feet above Ordnance-datum. This portion of 

 the plateau forms the water-parting between the rivers Bradford and 

 Wye, tributaries of the Derwent near Darley Dale, on the north-east, 

 and Bletch Brook, Bradbourne Brook, and Bentley Brook, tributaries 

 of the Dove near Ashbourne, on the south-west. The quarry is 

 being worked back into the south-western slope of the plateau. The 

 bottom of the quarry (into which runs a siding from the High Peak 

 Eailway) is 1090 feet above Ordnance-datum, and the top of it is 

 about 30 feet higher. 



If we stand on the top of the quarry, it is obvious that we are 

 standing on the edge of the limestone-plateau, and that the quarry 

 is cut in the south-western face of a small knoll or hillock on that 

 plateau. It is separated from another knoll on the north by a small 

 depression, which widens out into a valley lower down on the south- 

 western slope, and from Harbro' Rocks (1244 feet above Ordnance- 

 datum) by a small depression at Longcliffe Station, which point 

 forms a col at a height of 1057 feet above Ordnance-datum. 



The upper beds in the quarry consist of cherty limestone, and 

 the lower ones of more massive limestone. Some portions are 

 completely dolomitized along the joints ; but the lowest bed is a 

 pure white limestone, used for making limestone-setts. The highest 

 point of the hillock in which the quarry is situate is about 30 feel- 

 higher than the top of the swallow-hole mentioned below, and is a 

 short distance nearly due east of it. 



