S. V. Wood—The Vallejj System of 8.E. of England. 503 



of the Essex County Asylum, being compelled to increase their 

 accommodation, purchased an estate at Wickham Bishop, near 

 Witham, and commenced an artesian well on the summit of that 

 part of one of these arcs of the Canterbury system (the 4th in the 

 Phil. Mag. map, but the 3rd in the MS. map, counting from the 

 centre of disturbance) which runs through that place. The sinking 

 of this well and boring was watched by Mr. W. H. Dalton, of the 

 Geological Survey, as part of his duty when engaged in the survey 

 of the neighbourhood ; and a section on the true scale, drawn 

 through the ridge formed by this part of the arc, to show the 

 peculiar and (to all but myself) unexpected position which the 

 beds have been found to occupy in it, has lately been published 

 by him in the "Transactions of the Epping Forest and County 

 of Essex Naturalists Field Club " ; and this shows that there is 

 present in the ridge exactly such a fold as in the line of hypothetical 

 section given by me I showed ought to occur everywhere along 

 this arc, as well as along each repetition of it outwards and inwards. 



I can account for the incredulity with which the facts brought 

 forward by me more than seventeen years ago have hitherto been 

 regarded, only by supposing that no one has thought it worth while to 

 examine my case with that minuteness which is necessary for its 

 realization ; but now that the existence of the fold exactly at the 

 place, and in the precise form which I thus hypothetically predicated.^ 

 has been found, and its discovery has involved the waste of a large 

 sum of money (as from the failure of the strata in consequence of 

 this fold to hold water, the Asylum Committee have been obliged to 

 abandon their intention of using the estate for the purpose for which 

 it was purchased), my views may now meet with a less incredulous 

 regard than they have hitherto done. It must, however, be borne 

 in mind that though the fold, as I contend, exists in every one of 

 the arcs of each system, yet from its occupying not more than a 

 hundred yards or so of horizontal space transversely to the arc (as 

 seems to be the case at Wickham), it must everj^where be concealed, 

 unless some open section chances to occur immediately over it. 

 At another arc, however, of the same system as that to which the 

 Wickham ridge belongs, viz. that which is constituted by the 

 Cambridgeshire chalk escarpment, the occurrence of such a section 

 has enabled the Geological Survey since my paper and map to dis- 

 cover a similar fold in it ; and this is near Eoyston. 



From the greater detail and accuracy with which I extracted these 

 arcs in the MS. map annexed to the memoir in the Library of the 

 Geological Society, 1 was able further to show that a third series of 

 concentric arcs, spreading from a point of disturbance in the North 

 Sea off Yorkshire, had, by meeting those spreading out from the 

 Isle of Wight centre, co-operated with them in producing the valleys 

 which crossed the arcs of the Canterbury system ; and though it 

 would be but waste of print to attempt any explanation of the 

 features of so complex a case in this Magazine, it requires but a 

 glauce at this map to perceive that all of the three sets of arcs must 

 1 See foot-note at the end of the pnper. 



