914 



NATURE 



[December 22. 1923 



is the subject of a well-written paper by Miiw K. M. 

 Meek in tlic report of the Dove Marine I^lwratory 

 for 1022 23. I'ifty years ago the salmon fisheries of 

 the 'Jync were more than ten times as prosperous as 

 they are to-day, and almost conclusive evidence is 

 now given to show that the decline of this industry Ls 

 due to sewage pollution. The paper is of general 

 interest since it is illustrated by a series of curves 

 correlating the effect of sewage contamination upon 

 the oxygen content of the water. The result 01 an 

 experiment on Zoarces viviparus indicates that the 

 toxicity of the sewage is directly due to foreign sub- 

 stances in the sewage and not to the reduced oxygen 

 content of the water. It would be interesting to know 

 to what extent sewage must be tliluted in order that 

 this fish can continue to breed under experimental 

 conditions; also, what is the direct effect, if any, of 

 the reduced oxygen supply. 



Boundaries in the United States. — Bulletin 

 No. 689 of the United States Geological Survey is a 

 complete account of the boundaries, areas, geographic 

 centres and altitudes of all States in the United States, 

 including oversea possessions. It is a revised and 

 enlarged edition of a bulletin that was first published 

 in 1885 and has been republished with additions 

 several times since that date. A brief introduction 

 discusses how boundaries are established and changed, 

 but the greater part of the volume deals with the 

 boundaries of the different States. Full details of the 

 present position of the boundaries and of all past 

 changes are given, with detailed references to treaties 

 and other State documents. In addition to a number 

 of sketch maps, there is a large reproduction of the 

 second edition of the Mitchell map of the British and 

 French dominions in North America as printed in 

 1774 or 1775. This was the map that was used in 

 forming the peace treaties of 1782 and 1783, for in 

 spite of its imperfections it was the best available at 

 the time. A coloured map shows the routes of the 

 principal explorers from 1501 to 1844 in the territory 

 now covered by United States jurisdiction. The 

 publication contains a great deal of valuable material 

 for the study of the evolution of boundary lines and 

 frontiers. 



Philippine Earthquakes. — The Philippine archi- 

 pelago is one of the most active seismic regions in the 

 world ; yet, near its centre, lies the long narrow island 

 of Cebu, in which, for the last four centuries, almost 

 the only earthquakes felt have come from outside. 

 On this account, the earthquakes that may be con- 

 sidered as belonging to it are of interest, if only in 

 showing that historic time may be too brief to reveal 

 all the areas of seismic change. One earthquake that 

 caused slight damage in Cebu occurred in 1887, and a 

 second on February 28, 1922. The latter is the 

 subject of a brief report by the Rev. M. Saderra Mas6, 

 the historian of Philippine earthquakes (Bulletin of 

 the Weather Bureau, Manila, for February 1922). 

 The area of damage included the capital city Cebu and 

 the small island of Mactan to the east. In the channel 

 between the islands, beneath which the origin probably 

 lay, unusual movements of the sea were observed, and 

 on the same day, but at an unknown hour, the cable 

 crossing it was broken. 



Sub-Surface Geology in Oilfields. — Until the 

 last few yccirs, sub-surface structural analysis in 

 oilfield work tended to be a very haphazard process. 

 Too often subterranean structures have been described 

 in terms of mapped surface evidence, and methods 

 of correlation of well-log data have been in the main 

 of a somewhat crude character, until the technique 



NO. 2825, VOL. I 12] 



of palaeontology and petrology was acquired in dealing 

 with the evidence adduced from driuin^ operations. 

 Some r I < irts of petroleum geologists attached 



to the I tates Geological Survey have shown 



that the iiricssity for more detailed work of this 

 character is now fully appreciated, and a great deal 

 of minute investigation is hcing prosecutnl in this 

 connexion. It is therefore somewhat of a surprise 

 to see that in the case of the sub-su*^' ■• - <♦■•'<« "f the 

 Pershing oil and gas field. Osage < 1 <. 



the author, Mr. VV. W. Rubey, ha- 

 depending almost entirely on driller 

 well-logs, field -statistics, and the lik' , 

 more highly technical and certainly more c< 

 methods of study. It is open to doubt as t<' 

 graphical methods of interpreting oil-well beliavKnir 

 lead to really important evidence which may be i!-<'l 

 as a basis of deduction of subterranean < ' 

 and as a guide to the future course of devi 

 of the oilfield concerned. As criteria of k i 



circumstances, individual or even coUectiv* 

 performances are of doubtful value if studied NMtt)"i:t 

 reference to as comprehensive a knowledge of the 

 unexposed rocks as possible. It is not to be exi)e<.ii-d 

 of the average driller that he is trained in even the 

 elements of lithology ; his terminology is necessarily 

 crude and in many instances untrustworthy. It is 

 for the geologist to analyse and name the sampK-s, 

 just as it is his business to use those results for precise 

 correlation below ground. Thereafter, by co-ordina- 

 tion of such evidence and all other statistical data 

 furnished during the life-histor>' of each well, he is 

 in a position to supply the operators with all the 

 information necessary to economical development of 

 the field as a whole. 



Rainfall in Sumatra. — The Royal Magnetic and 

 Meteorological Observatory at Batavia has recently 

 published, in Verhandelingen No. 11, a summary of 

 rainfall in the northern part of " Sumatra's Oostkust," 

 by Dr. J. Boerema. The observations are made at 

 the official rainfall stations and the figures are not 

 used unless they cover a period of at least 5 years. 

 There are 288 stations available and in addition 

 22 stations in Atjeh and 4 in Tapanoeli. Monthl\- 

 and annual results have been calculated for a 

 normal period of 20 years. Maps for the year and 

 for each month show the areas of equal amount- 

 of rainfall for practically the whole country ; als< • 

 the months of maximum and minimum rainfall. T 

 is estimated by discussion that a monthly mean 

 rainfall calculated from 5 years' observations may 

 differ to the extent of 40 to 50 per cent, from the 

 average obtained from a long series of observations, 

 say 35 years ; in the case of 10 years' obseivatioiT;. 

 the deviations are reduced to about half that vc . 

 For 30 years the difference from the 35-year norai.il 

 is only 3 per cent. The rainfall increases from tht 

 coast to the mountains, the annual map showing .i 

 genercd rainfall of about 60 to 100 inches near thi 

 north-east coast to about 150 to 260 inches in the 

 mountains. An annual average of 263 inches is given 

 at Bandar Baroe. The rainiest season is October and 

 November, w^th a secondary maximum in April and 

 May. The double tropical periods of rainfall are 

 scarcely disturbed by the monsoons. The minimum 

 rainfall occurs in February and June. Statistics are 

 given of the monthly and annual amount and fre- 

 quency of rainfall at all stations. More than ordin- 

 ary' interest is associated with the carefully worked 

 results since Sumatra is divided by the equator and 

 falls about equally in the Northern and Southern 

 Hemispheres. Such discussions are of the highest 

 value to the world's meteorology-. 



