466 



NATURE 



[December 26, 1912 



tribes we now have a concise account of their 

 history, custoins, and mode of life, a description 

 of their country and the routes by which it can 

 be penetrated, and of the successive expeditions 

 directed against them. Colonel Wylly, who him- 

 self knows the ground, has done the work of con- 

 densing the material with much discretion and 

 ability!^ and the book, though in the nature of a 

 summary, is written in a graphic and readable 

 stvle. it does not profess to give detailed refer- 

 ences to the authorities on which it is based, and 

 ■ it is unfortunate that at least a bibliography of 

 the most important literature available for study 

 has not been supplied. A fine set of maps and a 

 good index add to the value of the book. Though 

 from its form it is unlikely to become popular 

 with the general reader, it will be indispensable 

 to' the soldier on duty on the frontier and to the 

 student of military history, while for the geo- 

 grapher and the ethnologist it, for the first time, 

 draws aside the veil which has hitherto concealed 

 a most interesting tract of country and tribes 

 which, in spite of their cruelty and fanaticism, 

 possess many admirable qualities. Now that 

 light lias been thrown upon them we may learn 

 how to understand them better and establish more 

 satisfactory relations with them. 



(3) From its geographical position Malta was 

 necessarily closely connected with that form of 

 eastern Mediterranean culture which finds its most 

 complete presentation in the discoveries made by 

 Sir A. Evans in Crete and by Schliemann at 

 Mycenae and other sites on the mainland of Greece. 

 Hence a monograph summarising the results of 

 the recent important excavations in Malta and a 

 discussion of their relation to those in other parts 

 of the Mediterranean and its border lands will 

 be welcomed by archaeologists. Mr. Bradley has 

 been personally engaged on the work of excava- 

 tion with Dr. Ashby and the local antiquaries, and 

 is thus in a position to undertake such a task. 



In 1910 a prehistoric well tomb was discovered 

 between Attard and Citta Vecchia, where, beneath 

 an upper Punic stratum, human bones mixed with a 

 deep red pigment were found associated with 

 pottery of an early type. About the same time. Prof. 

 Tagliaferro discovered a series of ossiferous caves 

 at Bur Meghez, between Valetta and Hagiar Kim, 

 in which numerous interments, also accompanied 

 by primitive pottery, were unearthed. Perhaps 

 most important of all is the discovery of the Hypo- 

 geum at Hal Safiflieni, near the head of the Great 

 Harbour. This important niegalithic monument 

 consists of two stories, the lower apparently used 

 as a place of storage, being provided with bin- 

 like structures, while above is a sanctuary which 

 seems to have been concealed from public view- 

 by a curtain. Mr. Bradley gives a valuable 

 account, accompanied by excellent photographs, 

 of these interesting remains and of the pottery 

 and other objects recovered from them. His 

 theory that the dolmen originated in a cave burial 

 and his survey of the prehistoric pottery deserve 

 attention. 



But he has not been content with describing 

 NO. 2252, VOL. 90] 



these remains and tracing their analogues in the 

 adjoining regions. The real object of his book, 

 he tells us, is to portray the psychological charac- 

 teristics of the pre-Aryan population of Europe 

 with a view to explain how a race so highly gifted 

 as the Cretan monuments show it to have been 

 fell almost without a struggle before the Aryan 

 invaders. This is a problem which is obviously 

 only indirectly connected with the archaeology of 

 Malta, though some side-lights useful for its 

 solution may ultimately be derived from the dis- 

 coveries in that island. But it raises a series of 

 complicated questions, such as the Egyptian, 

 Babylonian, or Phoenician influences in the eastern 

 Mediterranean, the origin of megalithic monu- 

 ments throughout the world, and so on, for the 

 solution of which he can scarcely claim to possess 

 the necessary qualifications. Such an inquiry is 

 probably much too serious to be undertaken by any 

 single scholar at the present time, and we trust 

 be content with a series of monographs dealing 

 with the varied phases of this widespread culture 

 before any comprehensive treatment of the subject 

 as a whole comes to be possible. 



NEW HYDROGEN SPECTRA. 



IN 1896 Prof. E. C. Pickering discovered a 

 series of lines in the spectrum of the star 

 ^ Puppis which has been attributed to hydrogen 

 in consequence of numerical relationship to the 

 Balmer series ordinarily observed in laboratory 

 experiments. From analogy with other spectra, 

 Rydberg further calculated the positions of lines 

 which would constitute the Principal series of 

 hydrogen, and the first line, at 4687'88, has been 

 identified with a line appearing in stars of the 

 fifth tj'pe. The ^ Puppis lines have since been 

 observed in the spectra of a few other stars, and 

 because they had not been found in the terrestrial 

 spectrum of hydrogen, even under the most promis- 

 ing conditions, they have commonly been con- 

 sidered to represent a modified form of hydrogen 

 which could only be produced ai very high tem- 

 peratures. Hence, Sir Norman Lockyer gave the 

 name " proto-hydrogen " to the gas which pro- 

 duces the lines in question, while others have 

 called it " cosmic " hydrogen. 



A further contribution to our knowledge of the 

 spectrum of hydrogen was communicated to the 

 Royal Astronomical Society on December 13 by 

 Mr. A. Fowler, who has succeeded in produc- 

 ing four lines of the Principal series, three of the 

 ^ Puppis series, and three lines of an ultra-violet 

 series which has not previously been suspected. 

 The new lines were obtained by passing a strong 

 condensed discharge through an ordinary Pliicker 

 tube containing a mixture of hydrogen and helium, 

 and it is remarkable that it was not found possible 

 to produce them from hydrogen alone, under 

 apparently identical conditions. At low pressures 

 the lines appeared in the bulbs, close to the junc- 

 tions with the capillary tube, and were then sharply 

 defined. At higher pressures the lines of the Prin- 

 cip.il and new series were very bright and broad 



