ON THE ERRATIC BLOCKS OF ENGLAND, WALES, AND IRELAND. 207 



county except the south side, extending from 6 to 60 miles, and from all 

 points of the compass except from the south. 



They comprise granites, syenites, slates, grits, sandstones, mountain 

 limestones, oolitic limestones, lias limestones, marl-stones, chalk-flints 

 coal and coal-shales, &c. 



The group is 290 feet above the sea-level and covers about 100 acres ; the 

 number counted was 500. They were turned out in an extensive system 

 of draining carried out over the whole area to a depth of 4i to 7 feet, in 

 widths varying from 1^ to 2 feet. All occur in drift, gravel, sand, and 

 clay. Many thousands of erratics must lie concealed under the remainder 

 of the area. 



The great ' Erratic,' called the ' Holy stone,' at Humberstone (briefly 

 alluded to in the Second Report for 1874, and more fully described in 

 the Sixth Report for 1878), one of the largest yet discovered in the mid- 

 land counties, is now entirely uncovered, and some fine photographs (on 

 a large scale) have been taken of it. The block is pentagonal in shape, 

 the sides are quite vertical, and are of the following dimensions in leno-th, 

 7 ft., 6 ft. 4 in., 5 ft., 5 ft. and 4 ft. 4 in. It may be observed that two of 

 the sides of 5 feet each are opposite to each other. The depth of the 

 sides is 5 feet. The longest axis is 10 feet, and the next in length (and 

 at right angles to it) is 9 feet. 



The vertical sides and corners of the block are as fresh as if recently 

 quarried, and no groovings can be seen upon them. The upper surface 

 (the longer axis of which lies N. and S.) has several deep irregular 

 grooves running N. and S., but these are considered to have been done 

 since the block was deposited, as it is thought, from reasons that cannot 

 be here entered upon, that it has been very much higher, and that a 

 considerable portion of the upper part has been worn away by natural 

 and artificial causes. 



The bottom of the block cannot be seen without turning it over, and 

 this would be a work of some labour. Careful calculation makes the 

 weight nearly 21 tons. 



The block rests on a denuded bed of the rhajtic formation, and the 

 material around it, which nearly covered it, is of recent accumulation, 

 so that originally it is thought to have stood quite exposed. The height 

 of the hill from which it is considered to have been brought is about 400 

 feet above the level of the sea, and is situated 6 miles N.W. The hill- 

 side on which the block now rests is about 240 feet above the sea, and 

 there is a river valley between these two points (at right angles to the 

 line of transit of the block) which is only 110 feet above the level of the 

 Bea. 



The proprietor, in obliging compliance with the request of the Com- 

 mittee, will take measures for its preservation. 



Hertfordshire. — Mr. H. George Fordham.P.G.S., presents the following 

 report on the Erratic Blocks of the parish of Ashwell. 



[Ordnance Maps— 1-inch, Sheet 46. N.E., and 25-inch, Parisli Map.] 



The village of Ashwell lies in the middle of the parish, on the Chalk 

 Marl and the lowest beds of the Lower Chalk, at the foot of a ridge of Lower 

 Chalk hills, from which the river Cam, or Rhee, rises on the east side of the 

 village. 



To the north the parish is flat, consisting of Chalk Marl, through which 

 the river cuts a narrow channel, and it just reaches the Gault in its ex- 

 treme northern point, about 2| miles from the village. 



