290 Transactions. — Geology. 



Ferry Hotel, Waiau-ua (29 miles distant from epicentrum),. 

 is built on rock which is cut ofi" from tlie earthquake-origin by 

 an alluvial valley ; it would therefore, in all probabilit}-, 

 receive less than the normal shock due to its distance, because 

 some of the waves may have been totally reflected upwards 

 before reaching it. This hotel is an old cob structure, and 

 manifestly it has not undergone such a severe shaking as 

 Woodbank or St. Helen's were subjected to. 



Leslie Hills (33^ miles distant from epicentrum) undoubt- 

 edly received a more severe shock than did Montrose or 

 Balmoral, and it is situated on the margin of an alluvial plain, 

 where the wave passed onwards into rock, and consequently 

 in a position where we might expect an increase in the 

 violence of the shock from total reflection upwards. The 

 same explanation applies to Highfield (46 miles distant), 

 where several chimneys were thrown down ; for it stands on 

 an alluvial terrace, with hills behind wdiich face westerly. 



St. Helen's certainly received a more severe shock than itij 

 distance from the epicentrum (32 miles) would warrant, 

 although it stands nearly in the middle of the eastern half 

 of the Hanmer Plains. But the evidence shows that the 

 wave emerged here at a high angle. Hams and bacon were 

 thrown off hooks ; a birdcage was also thrown off a hook, 

 and ice was thrown up out of a pool. Evidently the angle of 

 emergence was greater than usual, and I should account for 

 this, as well as for the hicreased intensity of the shock, by the 

 supposition that the spur between tlie Hanmer and the Per- 

 cival Rivers runs down under the alluvial plain below 

 St. Helen's and acted as an earthquake-reflector upwards. It 

 has been supposed that the ground on which St. Helen's is 

 built is swampy, and that that would account for the damage 

 done to the house ; but it would not account for the increase in 

 the angle of emergence, and, after seeing the locality, I feel 

 inclined to reject the swamp theory altogether. 



At Woodbank (28 miles distant) the shock was undoubtedly 

 more severe than its mere distance from the epicentrum would 

 explain. I do not take into consideration the brick portion of 

 the building, which was old and put up with bad mortar, but 

 the wooden part of the house, which was shifted bodily 

 2^in. Here, also, cob huts, not worse built than the 

 Ferry Hotel, were rendered quite uninhabitable, while the 

 Ferry Hotel, only one mile further from the epicentrum than 

 Woodbank, was scarcely injured. At W^oodbank, also, a 

 cement chimney-top was thrown up and then fell over on to 

 the roof of the wooden part of the house, which indicates not 

 only a very strong shock, but also a high angle of emergence. 

 This is conflrmed by Mr. Atkinson, who says that when 

 standing outside his house immediately after the first shock 



