January 1, 1890.] 



KNOWLEDGE 



63 



We should be glad to see a complete Natural History of 

 Hampstead. As Dr. Walker, whose lists are given, enume- 

 rates Mi/riojiddii, Ardclmidii, and Ent(im<isti-(ir<t among the 

 insect-faiuia (!), we may direct his attention, and that of 

 Professor Lobley, to a Xote nn the Fhidih nf thr H<iiiipnti'(iil 

 Ponds, by B. B. Woodward, Esq., in the Almtnict of I'ru- 

 (■cedimjs of the West London Sricntliiv Associdtiiin for March, 

 1876, which gives four amphibians, four fish, and ten 

 raollusks, besides water insects and Crustacea. A few of 

 the land-shells are recorded in Cooper's Flin-n Mi-troii(}l.itana, 

 and assuredly a glance through the Jowmd of the (Jufhctt 

 Microscopical Club will afford a goodly list of micro- 

 organisms. 



Local residents — that is, Londoners generally — might 

 do worse than purchase Professor Lobley's book and inter- 

 leave it for their own additions. — G. S. Bouluer. 



Thi' Hirer Karun ; an. Ojiciiinfl to British Commerce. By 

 W. F. AiNswoRTH, Ph.D., F.S.A., F.R.G.S. (W. H. 

 Allen & Co.) The Karun is the chief river of Persia, and, 

 in fact, from a commercial point of view, the only river of 

 any importance. By a treaty recently concluded with the 

 Shah, it has been opened to navigation, and consequently 

 to British commercial enterprise. Flowing as it does into 

 the head of the Persian Gulf, and connected as it is by 

 canal with the Shat-al-Arab (the stream formed by the 

 junction of the Euphrates and Tigris), it is manifestly a 

 water-way of great importance in the development of the 

 resources of a country which is perhaps as little known to 

 the Western World as any of the great Asiatic empires. 

 Under these circumstances, the publication of Dr. Ains- 

 worth's book is most opportune. Having himself ascended 

 the lower half of the river's course, the author is com- 

 petent to speak of the capabilities of the route, and, for 

 what his own experience failed to supply, he has liberally 

 availed himself of that of other Persian travellers and 

 explorers. The book consists of three parts , the first 

 supplies very full details of the whole of the navigable 

 course of the river, the towns on its banks, and the 

 facilities they offer respectively as trading stations. The 

 second discusses the (juestion of land communication, a 

 matter of eijual importance with the water-way, and one 

 which is apparently beset with great difficulties. The 

 third part deals with the natural products of the coimtry, 

 which are sufficiently varied and valuable to form an 

 attractive prospect for European enterprise. It is gratify- 

 ing to learn that there has lately been great increase in 

 tlie trade of the United Kingilom with Persia, the tonnage 

 employed for that purpose in the Persian Gulf having 

 increased in sixteen years from 1,200 to 70,000 tons, and 

 it is to be hoped that the recent treaty may be the means 

 of still further augmenting this total. On the opposite 

 side of the country the trade is of course wholly in the 

 hands of the Russians, who, by their Trans-caucasian rail- 

 ways and the navigation of the Caspian, are in a good 

 position to monopolize the whole of its commerce unless a 

 vigorous coini)etili(in is started on the only other seaboard. 

 To British capitalists, therefore, the question of the de- 

 velopment of trade with Persia is largely one of rivalry 

 with Russia. The country immediately around the Karun 

 is, as Dr. Ainsworth points out, rich in antiquarian 

 interest, and explorations would no doubt yield many 

 interesting results. There seems to be a curious mis- 

 print on p. Ill, where the river is stated to How from 

 S.8.W. to N.N.E., instead of in the opposite direction. 



A I'riiiier of Sciiliititre, By E. Hoscok IMiu.i.ins. (Cassoll 

 and Co., London.) This is a charmingly illustrated little 

 book written in a philosophic spirit and interesting to the 

 general reader as well as to the art student who has 

 adopted sculpture as a profession. Mr. MuUins is in 



favour of the student learning thoroughly the handicraft of 

 his art, and, as soon as he has acquired sufficient dexterity 

 in technique, applying himself to the study of nature and 

 the interpretation of his own time rather than to the 

 endless copying of classical models. Though students of 

 science generally appreciate the great importance of being 

 able to draw the objects they are studying, too few of 

 them as yet recognise the great value which a model pos- 

 sesses in explaining ideas involving three dimensions. 

 Mr. Mullins's book will give them some useful hints for 

 making models in both clay and wax. 



Moimt Vesurius : a Descriptire, Historical, and (ieoloijical 

 Account of the Vohano and its Surroundings. By .1. Logan 

 Lobley, F.G.S. (Roper & Drowley.) Probably no vol- 

 canic region has been so long and so well observed as that 

 around Vesuvius. The beautiful situation of the volcano 

 in one of the fairest and most frequented parts of Italy, 

 as well as the frequency and \'iolenee of the eruptions, 

 have fixed the attention of mankind on the changes going 

 on in the Bay of Naples. Pliny, Sir William Hamilton, 

 and a long series of careful observers have noted the 

 phenomena of successive eruptions, and speculated upon 

 tlie causes at work. Pi-of. Lobley reviews at length the 

 history of the moimtain and of the neighbouring volcanic 

 regions, and he gives a striking series of drawings of 

 Vesuvius illustrating the changes which have taken place 

 smce the great eruption of a.d. 79, when Pompeii was 

 destroyed. Perhaps the most interesting chapter is that 

 in which Prof. Lobley reviews the various hypotheses of 

 volcanic action which theorists have from time to time 

 maintained — while admitting that active volcanoes are 

 generally situated on the sea-coast, or beside rivers or 

 lakes. He thinks that insuperable difficulties exist in 

 explaining the method by which water can pass from the 

 sea to a deep source of volcanic action, since open fissures 

 would either not allow of water descending in the face of 

 the stream that would force it back, or they would them- 

 selves be the channels of emission for the lava, so that 

 volcanoes would be confined to the sea bottom. He dis- 

 misses as equally unsatisfactory the theory that water 

 may reach the regions where the melted lava is stored by 

 capillary transmission through rocks, while the lava can 

 only issue by fissures in the rock ; but at the same time 

 he admits that immense quantities of steam issue from 

 volcanic vents where lava is poured out, and that salt in 

 considerable quantities is found with the Vesuvian 

 minerals. He rejects the theory that the solid rocks 

 form only a thin skin over a sea of melted lava, and is 

 inclined to believe that there are local regions where the 

 rocks are melted and occasionally reach the surface as 

 lava. He assumes that " the primary cause of the 

 formation of fluid lava is the internal heat of the globe 

 inducing chemical, and possibly electrical, action in sub- 

 terranean regions where the chemical composition of the 

 rocks and their contained and associated minerals are 

 favourable ; and where, moreover, the conditions become 

 more favourable by the removal of the restraining vertical 

 pressure of the superincumbent rock masses, by the 

 counteracting lateral or tangential pressure produced by 

 secular cooling causing shrinkage." 



Charts of the CoHstellation.t from the Xorth I'ide to lietirccn 

 rt5 (cnd 40 dajrees of South Decliniition. By Akthuk Cot- 

 TAM. F.R.A.S. (London: E.Stanford.) This magnificent 

 series of stellar charts certainly forms one of the finest, if 

 not the finest delineations of the stars visible to the ob- 

 server in Central Europe. It is intended primarily for 

 the possessors of telescopes which are not mounted equa- 

 torially. The owners of such telescopes have hitherto had 



