320 



SCIENCE. 



[Vol. VI., No. 140. 



sity, St. Louis, who constituted the transit-of- 

 Venus party in New Zealand in 1882, carried on, 

 under the auspices of the coast survey, a series of 

 gravity determinations after the transit of Venus 

 was over, swinging pendulums — the same that had 

 been used by Major Herschel in India, England 

 and America— in New Zealand and Australia, at 

 Singapore, Tokio, San Francisco and Washing- 

 ton. 



This series served the valuable purpose of con- 

 necting together, differentially, several independent 

 systems of gravity determinations, and when 

 finally reduced may slightly change Professor 

 Mendenhall's Tokio value, but is not likely to 

 alter it materially. It is of some importance to 

 note that, of the determinations in the vicinity of 

 Japan, the excess at Tokio is the smallest ; those 

 at Sapporo and Kagoshima, near the northern and 

 southern extremities of the principal Japanese 

 islands, come next ; that at Naha, out m the ocean 

 off the Chinese coast, is stiU larger ; while the 

 Bonin islands, well out in the Pacific, give the 

 greatest excess yet observed. The value coming 

 nearest to this was also determined by Captain 

 Leutke at Ualan, one of the most south-eastern of 

 the Caroline group of islands, and about 5° north 

 of the equator. It would certainly be weU to re- 

 occupy this and others of Captain Leutke's stations, 

 in order to determine whether these abnormal 

 values of g may be actually increasing in the 

 Pacific. 



The eclipse party, under Professor Holden, to 

 Caroline island, 10° south of the equator and in 

 mid-Pacific, also made, under the auspices of the 

 coast survey, pendulum observations there, and at 

 Honolulu and San Fi-ancisco. These results, to- 

 gether with those of Messrs. Smith and Pritchett 

 will be awaited with interest. 



The more we study our globe the more irregular 

 do we find it in figure and density ; and it is evi- 

 dent that such work as that inaugurated by Pro- 

 fessor Mendenhall at Tokio, and that prosecuted 

 of late years by the coast survey in all parts of the 

 globe — where it could be economically done in con- 

 nection with other necessary scientific work — is 

 among the most important of modern conti'ibutions 

 to oiu- knowledge of the figure and dimensions of 

 the earth, and is a class of work which must be car- 

 ried out in connection with triangulation and astro- 

 nomical determinations of latitude and longitude, 

 before we can be at aU sure that we know with 

 sufficient precision the average value of the earth's 

 radius, which is the unit of length or base fine 

 from which we strike out from the earth into 

 celestial spaces, and upon which all our values of 

 planetary and stellar distances depend. 



H. M. Paul. 



GEOLOGICAL CHANGES IN NEW SOUTH 

 WALES.' 



From the close of the Pleistocene period to pres- 

 ent times the main physical features of New South 

 Wales liave remained pretty constant. In the Car- 

 boniferous period a large part of the country was 

 a stretch of ocean, the New England mountains 

 being but little older. The last main elevation oc- 

 curred early in Mesozoic times, and from that time 

 to the Pleistocene ]3eriod unceasing atmospheric 

 denuding, faultings and volcanic eruptions have 

 been at work shaping the country into valleys and 

 hills. The Pleistocene deposits are indicated by 

 vast accumulations of drift and diluvial sediment 

 derived from the erosion of the deep valleys in the 

 highlands when the rainfall was greater than at 

 present. That the rainf aU in this period was much 

 greater than it has since been is proved by the evi- 

 dence of great erosion in the highland's. 



The cause of this interesting pluvial period over 

 a large portion of the southern hemisphere — for its 

 effects have been observed in New Zealand, South 

 America and Soutli Africa — is directly connected 

 with the Glacial period of the northern hemisphere. 

 While the northern winter was so long and cold as 

 to induce a large accumulation of snow and ice, 

 that of the opposite hemisphere was short and 

 mild with long and cool summers. There was a 

 perpetual spring in the southern lands. When the 

 alternation took place, 10,500 years after, the Ant- 

 arctic ice was so extended as to produce on a larger 

 scale and nearer to the Australian continent, the 

 fogs, rain and snowstorms which now prevail in 

 the Antarctic ocean. The present glaciated con- 

 dition of the Antai'ctic regions being due to the 

 winter of the southern heaiisphere being in aphel- 

 ion, it may readily be perceived how these condi- 

 tions must have been intensified in the Pleistocene 

 period when the eccentricity was three and a half 

 times greater than it now is. It is also thought 

 that owing to the extreme difference between the 

 temperature of the south pole and that of the 

 tropics, the south-east trade winds would blow 

 with a greater force over a larger area, and so the 

 upper counter trades would return more heavily 

 laden with moisture. 



In the highest Australian mountain, Mount 

 Kosciusko, Dr. R. von Lendenfeld has recently 

 found proof of former glacial action. Traces of 

 glacial action were not seen lower than 5,800 feet 

 above the sea, and they did not cover an area of 

 more than 150 square miles. No glaciers exist 

 there now ; but patches of snow lie on the shel- 

 tered slopes and never disappear. It is interesting 



^Extract from Pjesident C. S. Wilkinson's address before 

 the annual meeting of the Linnsean society of New South 

 Wales, January 28, 1885. 



