November 5, 1908] 



NA TURE 



19 



spring, 53°-2 ; summer, 73°'0 ; autumn, 6o°>8 ; winter, 

 38°-7. The extremes observed were I3°S and 92°-5 ; the 

 periods of greatest cold and heat coincide approximately 

 with our own. The annual rainfall is about 56^ inches, 

 the average number of rain-days being log. There is a 

 fairly large rainfall in every month from January to Sep- 

 tember, especially in July, but only a slight fall during 

 the rest of the year. M. Ishida contributes an article on 

 the causes of the very heavy winter rainfall in the western 

 part of Honshu (facing the Sea of Japan). Abstracts of 

 these articles are given in English. 



The programme of the Institute of Archaeology and 

 .Anthropology in connection with the University of Liver- 

 pool is sufficiently ambitious ; but with working members 

 like Profs. Frazer, Newberry, and Myres it seems likely 

 to achieve success. The Institute, so far as British 

 archeology is concerned, proposes to conduct an archae- 

 ological and historical survey of North Wales ; and in the 

 course of excavations here it is hoped to train a body of 

 students who will be available for similar work abroad. 

 Besides this, schemes are on hand for excavations in 

 Egypt and British Honduras. As a record of its work, the 

 Institute has commenced the publication of a series of 



Annals of .Archajology and Anthropology," under the 

 editorship of Prof. Myres, of which the opening double 

 number for September has lately appeared. It is chiefly 

 devoted to Egyptian and Hittite archaeology. In the latter 

 field the most interesting contribution is the account by 

 Prof. Garstang of Dr. Winckler's excavations at Boghazkeui, 

 in Cappadocia, where the discovery of a copy of the 

 treaty between the Hittite monarch and Rameses the Great 

 fixes for the first time a definite date on which the 

 chronology of the Hittite empire can be safely based. 



Dr. G. a. Auden, medical superintendent under the 

 Educational Committee of Birmingham, has, with the 

 assistance of Miss Byron, done a useful service to 

 archaeology by issuing, side by side with the Danish and 

 German editions, an English version of the new guide 

 to the prehistoric collections in the Danish National 

 Museum at Copenhagen, which has been compiled by Dr. 

 Sophus Miiller. This is more than a catalogue of the 

 important series of specimens discovered in Danish soil, 

 because it will serve as a useful introduction to the study 

 of a branch of archaeology which has hitherto received too 

 little attention in this country. The manual is divided 

 into periods : the earlier and later Stone and Bronze ages ; 

 the pre-Roman and Roman Iron ages ; the post-Roman 

 Iron age; and, finally, the Viking period. It is illustrated 

 throughout with excellent engravings. As a concise 

 account of north European prehistoric antiquities it may 

 be usefully consulted side by side with the admirable guides 

 to the collections in the British Museum for which we 

 are indebted to Mr. C. H. Read. 



The bright lines or streaks seen when moonlight is re- 

 flected from water that is covered with regular ripples, or 

 the light of a lamp is reflected from a corrugated or 

 regularly polished surface, have often formed subjects for 

 questions in the few e.xaminations in which geometrical 

 optics figures in this country. In a paper in the Trans- 

 actions of the American Mathematical Society, ix., 3, Prof. 

 W. H. Roevcr discusses the general mathematical theory 

 of " brilliant points " on curves and surfaces, and his 

 paper is illustrated by photographs of the brilliant lines 

 on the surface of a circular saw which had been polished 

 in rotation. 



The riiysical Review for September contains an article 

 on the diffusion of salts in aqueous solutions, by Mr. R. 



NO. 2036, VOL. 79] 



Haskell, of the Massachusetts Institute of Technology, n 

 which the theory of diffusion is brought into line with 

 the dissociation theory of solutions. The dissolved salt is 

 taken as partially dissociated, and the theory is worked out 

 on the supposition that the diffusion of each molecule is 

 proportional to the rate of change per cm. of the concen- 

 tration of that molecule, whether dissociated or not, 

 multiplied by a constant called the diffusion constant, which 

 may have different values for a dissociated and for a non- 

 dissociated molecule. The measurements were made by 

 determining the electrical resistance between pairs of 

 platinum electrodes placed at different heights in a vertical 

 cylinder filled initially with pure water, with a layer of 

 concentrated solution at the bottom the strength of which 

 was maintained from an e.xternal reservoir. The author 

 finds the theory confirmed by his observations on thallium 

 sulphate and barium nitrate, and in both these cases the 

 diffusion constant for dissociated is double that for non- 

 dissociated molecules. 



We have received from Knowledge a specimen of the 

 Knowledge calculator, which has been designed by Major 

 B. Baden-Powell, and is put on the market at the low 

 price of 3s. 6d. , or 3s. 8d. by post from the Knowledge 

 Ofiice, 27 Chancery Lane. The calculator is in reality 

 a circular slide-rule made in card. As the diameter of the 

 circle is almost exactly 6-5 inches, it is equivalent in open- 

 ness of scale to a straight rule, divided from i to 10 only, 

 20} inches long, or to a straight rule divided from i to 100 

 of twice that length. A considerable number of gauge 

 points or conversion factors are marked round on the inner 

 card, and directions are given at the back for using the 

 instrument. The advantage of openness of scale of the 

 circular form has to be set against certain other advantages 

 of rules of the Gravet type which, in the writer's opinion, 

 are the more valuable ; still, whether one or other form is 

 to be preferred must, of course, be determined by each 

 user for himself. It does not seem probable that any other 

 form of circular rule made of card could be designed so 

 as to be more effective and inexpensive than this. 



The existence of a perchromic acid has been known for 

 the last sixty years, and the blue coloration resulting from 

 the action of sulphuric acid and hydrogen peroxide upon 

 chromates has taken its place as a useful test for 

 chromates. In spite of many researches, however, the 

 exact constitution of these perchromates has remained 

 doubtful. In the August number of the Berichte der 

 naturforschenden Gesellschaft zu Freiburg i. Br. there is 

 a paper by E. H. Riesenfield in which the whole of the 

 work on this subject is reviewed, and further experiments 

 described settling the composition of these compounds. 

 Four definite series of perchromates are described :— 

 HjCrO,, giving red salts with sodium, potassium, and 

 ammonium ; H,CrO,, giving blue perchromates ; KHjCrO, 

 and (NH^)H„CrO, ; the pyridine salt of the perchromic 

 acid, HCrOj ; and the ammonia addition product of per- 

 chromic anhydride, CrO,. .\\\ these compounds are 

 analogous, and are convertible the one into the other 

 under suitable conditions. 



Messrs. Willwms .\nd Norgate has published vol. viii. 

 of the new series of the Proceedings of the Aristotelian 

 Society. The volume contains Mr. Haldane's presidential 

 address on the methods of modern logic and the concep- 

 tion of infinity, the papers read before the society during 

 the session 1907-8, an abstract of the minutes of the pro- 

 ceedings of the society for the session, the rules, and a 

 list of officers and members of the society. The price of 

 the volume is los. 6d. net. 



