624 



NA TURE 



[May 13, 1922 



Research Items. 



Mexican ARCHiEOLOGY. — Since the days of the 

 Spanish occupation, the neighbourhood of Mexico 

 City has supplied a rich field for the exploration 

 of the antiquities of the pre-Columbian period. The 

 most impgrtant problem to be solved is the investiga- 

 tion of the strata showing the succession of cultures 

 — the Archaic, Toltec, that is pre-Aztec or Teoti- 

 huacan, and Aztec. Some progress in this direction 

 is outlined in a report by Mr. A. M. Tozzer, published 

 in Bulletin 74 of the Bureau of American Ethnology. 

 It is at present impossible to determine with exact- 

 ness the demarcation between the Toltec and Aztec 

 cultures, the inference being that the former flourished 

 towards the end of the first millenium a.d., and their 

 influence in Yucatan, at least, extended into the 

 fifteenth century. The artifacts discovered belong 

 principally to the Toltec culture, those of the Aztec 

 period being few in number and relatively unimpor- 

 tant, while a few things which are clearly pre-Toltec 

 or Archaic were encountered. It is interesting to 

 record that the methods of scientific archaeology are 

 being applied to this area, with expectations of 

 important discoveries in the near future. 



Fossil Man. — The Trustees of the British Museum 

 have just issued a third edition of the useful little 

 " Guide to the Fossil Remains of Man in the Depart- 

 ment of Geology and Palaeontology in the British 

 Museum (Natural History)." The guide was first 

 prepared on account of the interest in the study of 

 fossil man which had been aroused by the discovery 

 of the Piltdown Skull, and, as an introduction to the 

 specimens and casts exhibited, described the main 

 conclusions bearing on the question of the evolution 

 of man which are furnished by palaeontology, geology, 

 and anthropology. In the third edition, the later 

 part of the guide has been rewritten and extended to 

 include an account of the skull found in the Broken 

 Hill Mine, Rhodesia, in 1921, and two plates giving 

 four aspects of the skull have been added. The 

 more remarkable features of the skull are briefly 

 described, and the chief points in which it presents 

 similarities to the anthropoids. Neanderthal man, and 

 modern man are noted. As regards the question of 

 antiquity, it is pointed out that the life of the southern 

 hemisphere has been less progressive than that of the 

 northern, and the discovery of primitive species of 

 man in comparatively modern deposits was to be 

 expected. After summarising the evidence it is con- 

 cluded that either the accumulation of animal re- 

 mains in the cave is modern compared with deposits 

 left by palaeolithic cave men of Europe, or the animal 

 life of Rhodesia has changed more slowly than that 

 of Europe. 



Geology in New Zealand. — Prof. J. Park reviews 

 the structure of New Zealand in the Transactions of 

 the N.Z. Institute, vol. liii., 1921, a publication that 

 includes several papers on geology. As seems usual 

 in that enterprising and fortunate dominion, the 

 illustrations are of very fine quality. Brother Fergus 

 (M. J. Gilbert) describes the unconformable series of 

 the Waikato Heads district, where an " older-mass " 

 terminating in the post-Jurassic peneplain is capped 

 by a " younger-mass " of undetermined Cainozoic 

 age. Mr. J. A. Bartrum revises the geology of Great 

 Barrier Island, which guards the Hauraki Gulf on 

 the long promontory of the North Island ; he has 

 discovered a large area of delicately banded Cainozoic 

 rhyolites, previously described as slates and sinter. 

 Dr. C. A. Cotton's account of the warped land-surface 



NO. 2741, VOL. 109] 



near Port Nicholson, the harbour of Wellington, is 

 written with a true geographic instinct. 



The Galician Petroleum Industry. — On April 

 II, a paper on " Galicia and its Petroleum Industry," 

 by Mr. Albert Millar, was read at the Institute of 

 Petroleum Technologists, in which was embodied 

 technical and economic information of interest and 

 importance. The most important area at the present 

 time is still that of Boryslaw-Tustanowice-Mraznica, 

 this being the district of the largest producing wells 

 during the last fifteen years. As is well known, 

 however, there has been a steady decline in produc- 

 tion latterly, both in this area and in Gahcia as a 

 whole. While this causes alarm in certain quarters, 

 it has been the means of promoting the development of 

 new fields, chiefly those of Hordyscze, Ratoczyn, and 

 Opaka, in the Tustanowice district ; deep drilling at 

 Popiele and Jasienica, north-east of Boryslaw, has also 

 been undertaken. The bulk of the oil, which is, of 

 high grade and has a paraffin base, has hitherto been 

 obtained from Oligocene beds, together with a smaller 

 quantity from Eocene deposits. The Cretaceous 

 rocks, petroliferous in Western Galicia, are largely an 

 unknown factor as regards their ultimate commercial 

 value, as they have been penetrated only by a few 

 wells in the main region, and the results were incon- 

 clusive. Many experts beheve that water troubles 

 will prove more formidable at the Cretaceous horizon 

 than i? the case in the younger sands. Unquestion- 

 ably water is the greatest difficulty to contend with in 

 Galicia, and the calamitous experiences at Tustan- 

 owice, where "200 ton " wells were rapidly watered, 

 have done much to inspire misgiving as to future 

 prospects. Emulsification up to, and in some cases 

 more than, 20 per cent., has resulted in special methods 

 being devised for separating the oil. Zuber believed 

 this water to be the indication of exhaustion of the 

 field, but later observers favour its localisation to 

 Eocene sands. Gasoline extraction, started in 19x4, 

 has made much headway, 660,000 klg. being obtained 

 last year, a record production for Galicia. 



A New Method of Gauging the Discharge of 

 Rivers. — ^The method of gauging discharge based on 

 the principle underlying chemical hydrometry has 

 been in use for some time. It depends on the libera- 

 tion of a known quantity of salt in solution into the 

 river at a known rate and the estimation of the 

 amount of salt in the river some distance below the 

 inlet of the salt solution. This method has been 

 proved to give very accurate results, but its chief 

 disadvantage is the cumbersome nature of the pre- 

 parations involved, not to speak of the cost. In the 

 Scientific Proceedings of the Royal Dublin Society 

 for April, Prof. J. Joly describes a method of 

 utilising the same principles which gives even more 

 accurate results and is very economical in labour and 

 money. Radioactive measurements can be made with 

 great accuracy by a simple form of electroscope. In 

 the place of salt, which has to be introduced into the 

 river by the hundredweight, a few litres of a solution 

 containing a trace of radium is sufficient. Prof. Joly 

 proposes to use pitchblende dissolved in nitric acid 

 and then diluted with water. The solution is fed 

 into the river under constant pressure. The water 

 samples when collected are conveyed back to the 

 laboratory and stored in ordinary boiling flasks for 

 ten or twelve days. The emanation is then boiled 

 off into a small exhausted bulb, from which it is 

 introduced into the electroscope. At the end of three 

 hours the electroscope is read and the river discharge 

 can then be deduced. 



