320 Scientific Proceedings, Royal Dublin Society. 



to the quake ; for, although the tower in part fell, the chancel — 

 which is said not to be more than fortj'' years old — is considerably 

 injured. Old roofs, such as that on Little Wigborough, lost their 

 tiles. In Colchester a portion of the spire of the Congregational 

 church came down. This, however, was not very remarkable, as 

 the portion severed from it was a patch that had been added on 

 account of damages from a storm. 



3 and 4. Lath and Plaster and " Sheilings,'' or Wooden Houses. — 

 These are varieties of " frame houses." In the first the frames 

 are lathed and then plastered, while in the latter the frames 

 are covered with thiu wooden slabs or slats. As these classes of 

 houses can vibrate, especially the second, they suffered very little, 

 except some very old ones, from which the plaster or slabs were 

 shaken down ; many of them, however, had stacks of brick chim- 

 neys that fell and did considerable damage. 



GrEOLOGY OF THE ArEAS OF STRUCTURAL DESTRUCTION. 



From the geological map by my colleague, Mr. W. H. Dalton, 

 we learn that tlieir different areas are on, or at the margin of, ex- 

 posures of the London clay, while rarely has any damage occurred 

 on the younger accumulations. The destruction on it, however, is 

 confined to more or less small limited defined tracts. In connexion 

 with the geology, it may be mentioned that the evidence would 

 seem to suggest that the shock does not appear to have travelled 

 from one of the intensely affected areas to another, but that it was 

 in action in all at one and the same time, travelling in each in more 

 or less different directions, which, as pointed out by Dr. Taylor, 

 of Ipswich, seem to be due to the diversion of the shock by lines 

 of faults or breaks in the continuity of the strata. 



Wivenhoe. — This lies immediately N. E. of a part of the' es- 

 tuary of the Colne, the intense shock having affected a very small 

 tract which is margined to the southward by the break of the Colne 

 river valley i^. 75° W.) ; and adjoining this line the shock was 

 very severe, while it gradually decreased in intensity towards the 

 N.E., as a mile to the N.E. the houses in the north portion of the 

 village of Wivenhoe Cross were not injured. Eastward, in the 

 Alresford district, the damage was very slight compared to that at 

 Wivenhoe ; also to the west of the water at Rowhedge, although in 



