164 



NA TURE 



[December 9, 1909 



Contesting the views of Messrs. Ellis and Crawley, he 

 regards it as mainly based on a recognition by even savage 

 tribes of the physical dangers of interbreeding. He lays 

 stress on the dogma of Dr. Tylor that " exogamy was an 

 early method of political self-preservation " in widening 

 the influence of the clan by foreign alliances. Nothing is 

 more fatal to a clan than consanguineous marriage, " and 

 few things are ijiore vital to the welfare of a family, a 

 tribe, or a nation than the right ordering of the sexual 

 relations." 



In the September number of SpoJia Zeylanica, issued by 

 the Colombo Museum, Ceylon, Mr. P. Arunachalam 

 describes the ancient bronzes in the collection, and Mr. 

 D. VVickremasimghe contributes notes on the inscriptions 

 attached to them. The antiquity of the specimens is not 

 very great. King .Sigiri Kasypa rendered, we are told, " a 

 lasting service to the chronological history of Ceylon by 

 murdering his father in the fifth century a.d. ; but for 

 this signal act of parricide Ceylon dates would be in a 

 greater state of confusion than they are," the date of 

 this event separating the Mahawansa from the so-called 

 Sulawansa period, which terminated in 1815 a.d. All the 

 ancient bronzes in Ceylon belong to the period correspond- 

 ing to the Middle Ages of Europe. The catalogue is well 

 illustrated with photographs of the more notable specimens, 

 and is of interest as facilitating the comparison of Sinhalese 

 with Hindu art. 



The monthly review of cartography in Petermann's 

 Mitteilungen (p. 281) contains articles by Dr. Max Gasser 

 and Herr Moedebeck, president of the International Com- 

 mission for " Luftschifferkarten," on maps for use on 

 balloons and flying machines. The arrangement recom- 

 mended is a general map on a scale of 1/1,000,000, with 

 a smaller 1/200, 000-map for the details of routes. The 

 requirements of aerial navigation are dealt with in con- 

 siderable detail, and a system of conventional signs and 

 colours is proposed. It is suggested that the larger scale 

 map should show parallels at intervals of ten minutes and 

 meridians at intervals of twenty minutes, in accordance 

 with the methods for astronomical determination of posi- 

 tion worked out by Dr. Marcuses. Specimen maps accom- 

 pany the papers. 



In Symons's Meteorological Magazine for November Dr. 

 H. R. Mill gives a preliminary account of the remarkable 

 rainfall of October 26-28 in the south of England. On 

 the morning of October 26 the centre of a deep barometric 

 depression lay to the south of Ireland, and moved slowly 

 to the south-eastward ; on October 28 a change of direc- 

 tion took place, the centre moving north-easterly, the effect 

 being to enclose the south of England between the S.E. 

 and N.E. paths of the depression. A list of the records is 

 given for places where more than 2-5 inches of rain fell 

 in one day, and more than 4 inches in three consecutive 

 days. Both these conditions obtained in parts of Kent, 

 Sussex, and the Isle of Wight. Among the heaviest falls 

 during the three days, we note 6 inches at Ramsgate and 

 5-27 inches at Brighton ; so far as available records show, 

 no previous daily fall of 3 inches had been observed within 

 twenty miles of Brighton, where 3-60 inches fell on 

 October 26, or within forty miles of Broadstairs, where 

 3-14 inches fell on October 28. The month over the 

 country as a whole was by no means so wet as October, 

 1903. 



The Journal de Physique for November contains a 



description of an electromagnetic compass suitable for use 



on board ironclads, which was described before the Soci^t^ 



fran?aise de Physique more than a year ago by the 



NO. 2093, VOL. 82] 



inventor, M. Louis Dunoyer, and lias now been tested on 

 board one of the French cruisers. The apparatus consists 

 of a solenoid wound with two wires in parallel, which can 

 be rotated at a constant speed about a vertital axis to 

 which its own axis is perpendicular. The ends of each 

 of the two wires are connected to a two-part commutator 

 on the axis of rotation, and the two pairs of brushes 

 bearing on the commutators are set at right angles to 

 each other. From the brushes wires lead to the coils of 

 two moving coil galvanometers. The coils move about 

 horizontal axes at right angles to each other, and mirrors 

 attached to them produce images of two lines of light on 

 a horizontal ground-glass screen. As the solenoid rotates 

 the mean currents through the galvanometer coils are pro- 

 portional to the sine and cosine of the angle between the 

 axis of the ship and the horizontal component of the 

 earth's magnetic field, and the line joining the crossing 

 point of the two images to the centre of the screen gives 

 the direction and magnitude of that component. The 

 apparatus allows of ready compensation for both permanent 

 and temporary magnetism of the ship. As the ship is 

 " swung " the crossing point of the lines of light describes 

 on the glass screen an ellipse, the axis major of which 

 will, in general, be inclined to the direction of motion of 

 both the galvanometer coils. By rotating the solenoid with 

 respect to the commutators, the axis may be made to 

 coincide with one of these directions. It is then only 

 necessary to add resistance to the circuit of the coil which 

 gives the larger deflection to reduce the ellipse to a circle, 

 which would be the figure obtained if the earth's magnetic 

 field were undisturbed by the vessel. The method is 

 evidently very flexible, and admits of the observations being 

 taken in the cabin while the rotating solenoid is placed 

 on deck. 



,A PAPER on concrete pile foundations was read by Mr. 

 Alex. Melville on November 23 before the Institution of 

 Engineers and Shipbuilders in Scotland. Special reference 

 was made to the Simplex method, a system which Has been 

 specified by the Admiralty for the naval base at Rosyth. 

 This system is the invention of Mr. Frank Shuman, of 

 Philadelphia, who took out his first patents in 1903. The 

 essential principle lies in the driving of a tube or forme 

 constructed of lap-welded steel, the lower end of which 

 is closed by a loose point or by a pair of hinged jaws. 

 These jaws open w-hen the tube is being pulled up and 

 permit concrete to be passed through, filling up the space 

 left by the tube simultaneously with its withdrawal. The 

 jaws are, as it were, cut out of a cylinder of exactly the 

 same section as the sleeve, and so lie close against the 

 sides of the hole left by the sleeve as the forme is with- 

 drawn, thus offering no obstruction to the free passage of 

 the concrete. A driving cap is attached to the top of the 

 forme when the pile-driver is at work. On completion of 

 driving the cap is removed, and concrete is filled into the 

 forme to a height of several feet above the level of the 

 finished head of the pile in order to allow for sinking as 

 the forme is withdrawn, an operation performed by means 

 of tackle connected to the pile-driver. Such piles can be 

 inserted to any depth, and can be put in as close as 3 feet 

 from centre to centre ; reinforced piles on this system may 

 also be executed. The method has many advantages, and 

 has been very successfully applied in this and other 

 countries. 



Engineering for November 26 has an interesting leading 

 article on the encouragement of aviation. Although there 

 are some small signs of our waking up, everybody must 

 deplore our backwardness in taking a lively and efficient 

 interest in the new movement. It cannot be said, in re- 



