54 ME. H. W. M02fCKT0Iir ON THE 



it may not be Middle Bagshot. The difficulty is increased by the 

 existence of a somewhat similar bed of clay at the Hatch brickyard, 

 described by Mr. Hudleston.^ As, however, it will be shown later 

 on that both blue clay and pebbles do occur in admittedly Lower 

 Bagshot beds, there is no conclusive reason against the pebbles and 

 clays here and the clays at the Hatch brickyard being of that age. 

 Neither Mr. Herries nor the wi-iter ever doubted that the Dowles 

 Earm sandpit was Lower Bagshot. We never saw a Middle or 

 Upper Bagshot section in any way resembling it. 



WoTcirigliam. I think that there is now no suggestion of Upper 

 Bagshot here. 



Coppid Beech Lane (also called Buckhurst). Mapped as Lower 

 Bagshot ; a considerable thickness of Upper Bagshot is shown in 

 Dr. Irving's diagram in vol. sliii. of this Journal. See also p. 386 

 of that vol. There is a road-cutting extending nearly to the top 

 of the hill showing yellow sand with clay laminae, and there was 

 last year an excellent section in a pit on the south side of the high 

 road, just above Amen Corner, in a triangle formed by cross-roads. 

 The section was as follows in September 1890 : — 



\. Gravel 4 feet, resting very irregularly on 



2. Yellow and orange-coloured sand, very beautifully false-bedded, vs^ith many 

 layers of white clay (Bagshot Beds), 5 feet. 



The section was 150 feet long and a very good one. I never 

 saw any bed like that shown in it in either the Upper or Middle 

 Bagshot, and have no doubt that the whole hill is Lower Bagshot. 



Bracknell. Mapped as Lower Bagshot, but Upper and Middle 

 Bagshot are claimed here by Dr. Irving. The evidence appears to 

 me clearly sufficient to show that there is no Upper Bagshot here, 

 for there is green sand, either Middle Bagshot or debris of that 

 formation, at the highest point, Bill Hill. It is possible, therefore, 

 that a small Middle Bagshot outlier occurs there. Here, as in the 

 other cases, I quite agree with Dr. Irving that it is more satis- 

 factory to argue the question out on the ground than at a distance, 

 and I have been over it again and again both alone and with 

 Mr. "W. H. Hudleston, Mr. J. H. Blake, and Mr. H. S. Herries. It 

 is not easy to explain in a few words how very clear the matter 

 really is when one walks from the Easthampstead Caesar's Camp to 

 Bracknell. 



The green sands of the Middle Bagshot crop out above the 300- 

 f eet contour at Caesar's Camp, there is no sign of them at Easthamp- 

 stead Church hill, 285 feet above O.D., but at Bill Hill (Bracknell) 

 we find some green sand at the top of the hill over 300 feet above 

 O.D. This interesting fact was discovered by Mr. Herries in 1888, 

 and independently by Mr. Whitaker, I believe, in 1890.^ 



Everything below the green sand of Bill Hill appears to be 

 Lower Bagshot, and there are thoroughly satisfactory Lower Bag- 



1 Quart. Journ. Geol. Soc. vol. xliii. (1887) p. 448. 

 ^ Ibid. vol. xlvii. Proc. p. 4. 



