Secondary Beds of Northern Australia. 



117 



Locality. 



Apia, N. Pacific ... 

 Lyttleton, N.Z. ... 



Sydney 



Adelaide 



King George's Sound 



Greenwich Time 



of 



Occurrence. 



D. H. M. 



14 2 28 



14 4 20 



14 6 10 



14 11 40 



14 12 28 



Time 

 Occupied 



by 

 Transit. 



15.48 

 17.36 

 17.30 

 2500 

 25.30 



Approx. 

 Distance 

 from 

 Callao. 

 Naut. 

 Miles. 



6590 

 5720 

 6907 

 7383 

 7846 



Rate of 



Transit. 



Miles per 



Hour. 



417 

 327 

 394 

 295 



He pointed out that there appeared to be a retardation of 

 the wave as the distance from the centre of disturbance 

 increased ; and that the late hour at which it was felt at 

 Adelaide would be accounted for by the position of that 

 place with respect to the southern coast line of Australia. 

 It was also suggested that the apparent retardation might 

 be the result of assuming the centre of disturbance too 

 far east from the Australian coast : at Callao, for instance, 

 whilst it might really have been in the Pacific a long way 

 to the west of that place. If such were the case it would 

 make the rates of the wave transit much more equable. 

 The average rate of transit, omitting Adelaide, was 381 

 miles per hour ; in the great earthquake at Simoda in 

 Japan in 1854, the rate of transit, from observations made 

 at San Francisco, was 370 miles per hour.* 



Art. XX. — Notes on the Secondary Beds of Northern 

 Australia. By H. A. Thompson, Esq. 



[Read by Mr. Rawlings, 9th November, 1868.] 



Some time ago a considerable degree of interest was taken 

 in the papers read by Professor M'Coy, bringing under the 

 notice of the Royal Society the existence of secondary 

 rocks on this continent, as indicated by the fossil bones 

 of the ichthyosaurus and pleisiosaurus, and cretaceous 

 shells discovered on the Flinders River, near the Gulf of 

 Carpentaria. 



Having lately crossed the country where these organic 

 remains were found, it may be of some interest to commu- 

 nicate the few observations that were made in the course of 

 a rapid journey from Cleveland Bay on the east coast to the 



* Mallet's Report en Earthquakes. Brit. Assoc. Report, 1858, page 126. 



