December 26, 1918] 



NATURE 



js and r< ptiles. Croi odili - maj assist in 

 making a rivei Is, though 



bushbucks, waterbucks, hippopotami, and elephants 

 .if nol influenced bj them. Antelopes and other 

 ungulates seem to h oi water infested b; 



crocodiles. The paper also considers the geoj 

 aspects of the distribution of nativi tribes in East 

 Africa. 



M. Moussu, who mad< an investigational journey 

 into north-easi Morocco in 1017, has discovered .1 

 certain number of outcrops which point to the exist- 

 ence of petroleum deposits, especially .1- gypsum and 

 gypsum-clays occur frequently in the neighbourhood. 

 The three principal outcrops are at the Arab villages of 

 Ouled-Slama, Kohlott, and Khairett. The principal of 

 these outcrops was found ;it the first-named place, 

 which is a short distance from the military station of the 

 - Cheragas. The oil- an probably of a heavy 

 or bituminous nature. They ooze out of the ground 

 in wet weather in the form of emulsion, and there is 



an absence of vegetation where they occur. From 

 the main outcrop the writer was able to collect a few 

 litn— of the product. According to the Bulletin tic In 



d' Encouragement pom I'lndustrie Natipnale 

 mber-October, 1918, this product is a heavy 

 brown (nearly black) oil, which ris( - in the form of 

 emulsion in the salt-water of the watercourse. This 

 sample was distilled at temperatures ranging from oo° 

 to 225° C, and gave about 96 per cent, of distillates 

 of a density of from 800 to 830, the result being a 

 very pure kerosene. The quantity oi ethei and petrol 



small indeed. It is probable that these con- 

 stituents evaporate owing to the hi at at the surface of 



■<>ps. < >n Mir- other hand, the yield of lamp- 

 oil i- very high and the residue very low. Since the 



1 13 the author exti nd ovei 

 kilometres, it is reasonable to assume the existence of 

 others. 



Zeiischrifi des Vereines deutscher Ingenieure 



last Dr. (i. Rohn discusses the ques- 



tion of Germany's textile requirements in the light of 



..1 economic boycott of that county 

 Entente Towers, and brief!) reviews what has already 

 omplished in the way of finding substitutes. 

 A certain amount of success has been attained in 

 nettle cultivation. Although the yield of fibres from 

 nettles is only 6 to 7 per on!, of the weight of the 

 plant, the fibre has valuable properties, being very 

 fine and smooth and strong. Since the war broke Out 

 some fifty processes for utilising nettle-fibres ha 

 It is though: that 1,000.000 hectares 

 lands could be planted with nettles, producii 

 ns of fibres annually. The author als< 



made with wood-fibres, especially from 

 the conifers. Experiments have been going on for 

 some time with the view of extracting the fil 



itment, and sui ss has reu a hi 



I investigate directions. 



taken place, 100, in the production of 

 yarns from paper-stock, a numbi r of companies having 



5 to i 1 - i 11 I'iirck Co.'s 

 The method of obtaining yarn from paper itself is 

 outlined, and it is said that this method of 

 wood is expected to render valuable service to <■ 

 in future. 



0114 France has mad' great strides in the 

 production of acetate of cellulose for use as an 

 aeroplane dope, for kinematograph films, and for non- 

 inflammable celluloids for various general pi 

 The Bulletin de la ouragement pour 



I'Industrie Nationale for September-October la 

 particulars of what has been accomplished in thi 



2565, VOL. I02] 



facture both of the acetate oi cellulose itself and of 

 the acetic add, solvents, etc. Various processes are 

 employed, and the manufacture is carried on at a 

 number of chemical factories which had had no ex- 

 perience in its production until the necessities of war 

 made it imperative for them to take it up. 



In the Journal of the Washington Academv of 

 Sciences for October [9 Mr. L. W. Austin describes 

 a new method of using contact detectors in radio- 

 telegraphic measurements. The sensitive vacuum 

 and tellurium platinum thermo-elements have re- 

 sistances which vary with the current, and are 

 either slow in action or difficult to make and 

 transport. They have therefore been replaced in 

 the Naval Radio Laboratory of the United States 

 by contact detectors in series with high-resist 

 galvanometers shunted by paper condensers of a 

 microfarad capacity. The detector and galvanometer 

 are shunted by a resistance of a few ohms. The sensi- 

 tivity of the arrangement is greater than that of the 

 best vacuum thermo-elements of the same equivalent 

 resistance, and the deflections are proportional to the 

 square of the radio current, except in the case of the 

 galena detector, which shows a slight deviation from 

 the law. 



When a canal connects two rivers situated at 

 different levels, and the ordinary chamber lock is used 

 to pass traffic from the higher to the lower level, the 

 taken from the higher-level stream is often con- 

 able. A German firm has now patented a system 

 of "dry" lock (Zeitschrift des Vereines deutscher In- 

 genieuri October 19 and 26, 1918), in which the 

 ordinary lock-chamber is replaced by a concrete 

 basin permanently filled to a definite level with 

 water. In this are immersed powerful floats, 

 also made of concrete, running on runners on 

 the side of the basin. Connected by suitable 

 means to the float is a trough, which carries the 

 I to be transported from the high to the low 

 level, or vice versa. The floats are capable of sup- 

 porting the carriage, the trough, and the vessel trans- 

 ported. Now supposing it is desired to ship a vessel 

 from the higher to the lower level, all that has to 

 be done when the vessel is shipped into the conveying 

 trough (by suitable gear) is to overcome the buoyancy 

 of tiie floats by a suitable prime mover, i.e. the floats 

 are immersed until the trough is on a level with the 

 lower sluice-head. The reverse operation is followed 

 when shipping from low to high level. An installa- 

 tion of this kind is now working on the Neckar- ' 

 Danube Canal, and is said to offer considerable advan- 

 over the ordinary system of lock or the various 

 tvpes of ferrying gear hitherto used. 



Tin-: Cambridge University Press has in prepara- 

 tion, for appearance in its Cambridge Technical 

 Series, " Architectural Building Construction," W. R. 

 id and F. E. Drury, vols. ii. and iit. ; " Elec- 

 trical Engineering," Dr. T. C. Baillie, vol. ii.; "Auto- 

 mobile Engineering," A Graham Clarke; "Electro- 

 technical Measurements," \. E. Moore and F. Shaw; 



Paper: Its Uses and Testing," S. Leicester; 

 "Mining Geology," Prof. G. Knox and S. Ratcliffe- 

 Fllis; " Textile Calculations — Materials, Yarns, and 

 Fabrics," A. M. Bell ; "Laboratory Note-book for 

 Applied Mechanics and Heat Engines," F. Boulden; 

 "Elements of Applied Optics," W. R. Bowi 

 trie Installations." C. W. Hill; "Accounting," J. B. 

 Wardhaugh; "Chemistry for Textile Students," 

 B. North and N. Bland; "Dveing and Cleaning, 

 F. W. Walker; and "Experimental Building Science. 

 L L. Manson vol. ii. 



