Decembeb 1, 1891.] 



KNOWLEDGE. 



233 



frequently displays in detecting fundamental similarities 

 in widely different customs. He deals chiefly with the 

 subjects of marriage, government and religious rites, but 

 the pictures he draws do not represent things as they now 

 are, but rather as they were half a century ago, before 

 civilization had tampered much with the tribes in question ; 

 for, as tha author states, " scarcely any primitive folk are 

 now in existence ; soon there will be none." The pictures 

 of savage life are often horrible and disgusting enough, 

 completely refuting the pleasing theory of the " noble 

 sivage." But even in the most disgusting practices and 

 the most degraded rites, M. Reclus again and again finds 

 ideas similar to those that lie at the root of many of the 

 most respectable institutions of the civilized world. How- 

 ever, as degeneration and decline are admittedly factors in 

 human history as well as progress and growth, it does not 

 always seem clear whether, in the strange customs of these 

 so-called primitive races, we may not be dealing with 

 deteriorated remnants of something that was once nobler 

 and better, rather than with the initial stages of that which 

 in other nations, and under a more favourable environ- 

 ment, has developed into modern civilization ; whether we 

 have not debased relics instead of undeveloped germs ; 

 whether in fact, the name /lyimitire folk, if taken in its 

 literal sense, may not possibly involve a b3gging of the 

 question. But however this may be, there is no question 

 that in the book before us we have a valuable and interest- 

 ing contribution to the literature of ethnology, as well as a 

 series of essays which will stimulate thought and encourage j 

 enquiry. 



British Ferns. By E. .J. Lowe, F.R.S. (Swan Sonnen- 

 schein and Co.) —This is the fern-book of the "Young 

 Collector Series," and as a record of the distribution and 

 variation of our British ferns it is a marvellous 

 shilling's-worth, and represents an enormous amount of 

 careful work. The author has aimed high, so high indeed 

 that we are inclined to wonder where the "young collectors" 

 are to be found whose wants will be exactly met by this 

 little book. One of his chief aims appears to hare been 

 to illustrate the extreme flexibility of type which ferns 

 exhibit, and in this he has certainly succeeded admirably. 

 A very large proportion of the book is taken up with the 

 enumeration and brief characterization of varieties of the 

 difl'erent British species, amongst which the common 

 hart's tongue attains the maximum of variation ; to this 

 species alone 28 pages are allotted for the description of 

 upwards of 400 varieties. So much space is occupied with 

 this exhaustive treatment of varieties that no room is left 

 for such matters as the generalities of fern structure and 

 development, the distinctions between ferns and other 

 plants, &c., some of which one might fairly expect to find 

 explained in a beginner's text-book, written on scientific 

 lines. The fern collector who wishes to make use of this 

 book must lay his foundations elsewhere, and when he has 

 acquired a good general knowledge of his subject, he can 

 use Mr. Lowe's help in the study of varieties to his lieart's 

 content. Some useful hints are added as to fern growing 

 and collecting, and some remarkable varieties are nicely 

 figured. 



On Surrci/ Hills. By "A Son of the Marshes" (Black- 

 wood and Sons). — No more delightful book has come from 

 the pen of the Kentish naturalist who, under the above nam 

 (If iiliiini', has so often charmed the readers of " Blackwood," 

 than this collection of essays on Nature as she is to be seen 

 in tlie wilds of Surrey. It seems strange to talk of wilds 

 in connection with a county into which suburban hfe is so 

 rapidly pushing its way; and yet, as none know bettor than 

 tiiose who have boon there, within little more than an hour 

 from the roar and din of the Metropolis there aro to be 



found on the Surrey hills places as lovely and silent as 

 though they were in the remote Highlands of Scotland, 

 where some of the fast-diminishing wild fauna of our islands 

 still flourish comparatively unmolested. These little 

 visited, but lovely and picturesque, spots were for many 

 years the arena of our naturalist's observations, and in this 

 ioook, with the assistance of the editorial pen of Mrs. J. A. 

 Owen, he has recorded his impressions in simple but vivid 

 pictures which cannot fail to interest and delight the 

 reader. The accuracy of his notes proves him a keen and 

 patient observer, in ardent sympathy with Nature. He is 

 never better pleased than when watching the wild creatui-es 

 of hill and dale, roadside and stream. Bird, beast, fish, 

 or insect, it is all one to him : he loves Nature for her own 

 sakcy and wherever life of any sort disports itself there is 

 he to be found, early and late, playing the spy upon it, and 

 enjoying to the full the novelties of the scene. There is 

 an air of freshness and freedom about these realistic 

 sketches that is quite exhilarating, while the genial spirit 

 which pervades them, the strong human interest exhibited, 

 and the frequent touches of humour, combine to make " A 

 Son of the Slarshes " a capital companion. 



An Account of British Fliis (Diptera). Part I. By the 

 Hon. M. Cordeha E. Leigh and F. V. Theobald, B.A. 

 (Elliot Stock). At last we are to have a popular book on 

 British Flies. The authors aim at catering for the wants 

 of the young student of Dipterology, and they hope to be 

 able also to entice to their ranks some stray collectors from 

 amongst the devotees of the more popular orders of 

 Butterflies and Beetles. With a courage which deserves 

 success, they have undertaken the herculean task of 

 describing the enormous host of British Diptera, large 

 enough in Walker's time, but greatly augmented since the 

 publication of " Insecta Britannica," forty years ago. Six 

 parts are to be issued annually ; the first, which has just 

 appeared, contains a concise sketch of fossil Diptera, an 

 account of various classifications of flies, and descriptions 

 of some species of fleis. Life-histories, especially of 

 agricultural pests, are to be fully dealt with, and occasional 

 illustrations are to be added ; those in the present number 

 are scarcely up to the mark, the figure of the human flea 

 especially being decidedly unsatisfactory. The classifica- 

 tion followed will be that adopted by Mr. Verrall in his 

 recently published list. 



EXPLOSIONS ON PETROLEUM VESSELS. 



I!y UlCHKHI) P.EYN(iN. F.R.(i.S. 



THERE is probably no department of British industry 

 that has developed with such phenomenal rapidity 

 as the Petroleum trade, and so far as present 

 appearances are concerned there is every prospect 

 of it undergoing much further expansion. The 

 earlier shipments to this country were conveyed in barrels, 

 but the evolution of the tank steamer has completely 

 revolutionized the economics of the Peti-oleum trade. It 

 is proposed in the present pajior to discuss the adaptability 

 of existent methods of transit to the requirements rendered 

 necessary by the over-sea conveyance of crude Petroleum 

 with its accompanying inflammable vapours. 



Crude Petroleum or Naphtha may be described as an 

 inflammable liquid hydrocarbon, or rather as a compound 

 of several hydrocarbons. According to some authorities 

 these are three in number: C^ Hi-. C^^ Hj„, and C^,^ H,.;. 

 Each of these compounds has a difl'erent boiling point, that 

 of the last named being the highest. The ordinary 

 Petroleum of commerce boils at the low temperature of 

 120 ' Fahrenheit, and is exceedingly volatile. Of the native 



