194 



NATURE 



[August ii, 1910 



sophical Society and of the American Pnysical Society in 

 April, 1909. Instead of drawing curves showing the varia- 

 tions in the diurnal ranges of the magnetic elements with 

 solar activity, as is most frequently done, curves were 

 constructed showing the effects of the magnetic disturbances 

 experienced by the earth during the period April, 1906, to 

 December, 1909, at the Coast and Geodetic Survey mag- 

 netic observatories, on the absolute values of the magnetic 

 (jements, and especially upon the intensity of magnetisa- 

 tion. This latter curve had been drawn for the first time ; 

 when it was compared with the curves showing the varia- 

 tion in solar activity, during the same period, as mani- 

 fested by sun-spot frequency, sun-spot area, and calcium 

 flocculi area, then the interesting result was obtained that 

 " the intensity of magnetisation of the earth in general 

 decreases with increase in solar activity." 



_ In other words, the average or residual effect of magnetic 

 disturbances, in general, is equivalent to that which would 

 result by the superposition of a magnetic system opposite 

 to the earth's own field, i.e. a demagnetising or induction 

 system of magnetic forces. The north magnetic pole of 

 this superposed system is, in general, in high south lati- 

 tude instead of high north latitude, as is the case generally 

 for the small " S " disturbances already discussed. 



Hence for the larger Aisturhance systems, the electric 

 currents which we may suppose to cause the effects would 

 circulate around the earth, for negative ions, from east to 

 west, i.e. contrary to the negative currents for the " S " 

 disturbances, but this time in strict accordance with the 

 direction in which a kathode ray coming from the sun 

 would be deflected by the earth's magnetic field. 



For _ these big disturbances, accordingly, the times of 

 beginning, if they can be accurately obtained, will show 

 an increase going round the earth westwardly. .\ good 

 example is the most remarkable disturbance of which 

 there is any record, viz. that of September 2S last. Here 

 are the times for two sudden deflections at the beginning 

 of the storm, as scaled by Mr. R. L. Faris, of the I'.S. 

 Coast and Geodetic Survey, from the horizontal intensity 

 magnetograms of the five Coast and Geodetic Survey 

 magnetic observatories : — 



No. 



nwich 1 





: Sept. 



Difference No. 7-N0. 8 

 Me?n Diffrrence ... 



■62 



■i'23 



The average latitude for the two groups Nos. 7 and 8 is, 

 respectively, 32° N. and 39° N., and the average longitude 

 79° W. and 147° W. It is accordingly found that this 

 particular disturbance was propagated from stations in the 

 eastern part of the United States to stations in the eastern 

 Pacific Ocean about two and a half times slower than was 

 found for the simple " S " disturbances, hence roughly at 

 the rate of 2600 miles per minute, against 6700 miles for 

 the latter cases. It is not to be assumed at present, how- 

 ever, that the big disturbances progress over the whole 

 earth at a uniform rate. Their motions appear much more 

 complicated than for the " S " cases. 



Accordingly, so far as the big disturbances in general 

 are concerned, the kathode-ray theory of Birkeland and 

 Stormer fulfils the test regarding direction of progression 

 of the disturbance over portions of the earth, and as far 

 as the direction in which the negative electric currents 

 must, in general, go, as found from the preliminary 

 analyses above mentioned. Whether the theory will bear 

 the application of quantitative tests cannot be discussed 

 now. The main thing is to have working hypotheses to 

 which rigid tests can be applied. 



Should the electric-conduction theory above proposed to 



NO. 2128, VOL. 84] 



account for the disturbances there considered find further 

 confirmation, the way is opened to a possible corpuscular 

 theory of terrestrial inagnetism. On the basis of such a 

 theory, a number of the puzzling features of the distribu- 

 tion of the earth's magnetism and of its variations can 

 readily be explained. L. A. Bauer. 



UNIVERSITY AND EDUCATIONAL 

 INTKT.LIGENCE. 

 We have received a copy of the " Livingstone College 

 Year Book " for 1910. It contains college news, letters 

 from old students detailing their experiences, a review of 

 a year's progress in tropical medicine, &c. The training 

 given at Livingstone College (a nine months' course) is 

 designed to educate missionaries going to tropical countries 

 in the elements of medicine, so far as they are required 

 for the prevention of disease and the recognition and treat- 

 ment of common accidents and diseases. 



Indiana University, says Science, owns an experimental 

 cave farm near Mitchell, Indiana, and has established a 

 small laboratory there primarily for cave work. Cement 

 pools have been placed inside and outside the caves, and 

 give opportunities for breeding cave animals in the light 

 and outside forms in the dark. The ' University offers a 

 100/. fellowship, in addition to a furnished cottage, to any- 

 one who has had sufficient training to take up such work. 

 Applications should be sent to Mr. F. Payne, Winona 

 Lake, Indiana. 



We have received a copy of the handbook of the faculty 

 of engineering at University College, London, for next 

 session. The faculty includes the departments of 

 mechanical, electrical, civil, and municipal engineering, 

 and is intended to provide a systematic training for students 

 who wish to devote themselves to engineering. It has 

 been recognised by the Board of Trade as providing suitable 

 technical training for marine engineers, and its courses 

 also meet the needs of students who intend to enter for 

 engineering appointments in the various public services. 

 Prof. J. A. Fleming, F.R.S., is the dean, and Prof. J. D. 

 Cormack the vice-dean, of the faculty. 



The governing body of the Imperial College of Science 

 and Technology at South Kensington last year awarded 

 two scholarships for research in connection with aero- 

 nautics. The students have held their scholarships at the 

 National Physical Laboratory at Teddington. We learn 

 from the Times of August 5 that an additional scholarship 

 is now being offered for award at an early date by the 

 governors of the college. The scholarship will be tenable 

 for one year, and will consist of exemption from fees, 

 together with a maintenance allowance at rates fi.xed with 

 regard to the circumstances of the case, the value of the 

 scholarship being not less than 50/. and not more than 

 i5oi. a year. It is open to any properly qualified in- 

 dividual, irrespective of residence or place of education. 

 At Regent Street Polytechnic, too, the courses in aero- 

 engineering are to be developed. A second-year course of 

 aerodynamics is being arranged for students who have 

 qualified in the first year's work in aero-engineering 

 inaugurated during last session. The course will be open 

 to other persons wlio can provide evidence that they possess 

 the requisite knowledge of applied mathematics. Special 

 instruction in workshop practice relating to aeroplanes 

 and airships will be given, and students will receive help 

 in making gliders and working models of different types 

 of aerial craft they may be interested in. 



The calendar of the Edinburgh and East of Scotland 

 College of .Agriculture for 1910-11 provides full informa- 

 tion as to the courses of instruction offered to pupils for 

 the coming session. The college was founded in 190 1 with 

 the object of providing for agricultural education and re- 

 search in the central and south-eastern counties of Scot- 

 land. Its classes are arranged in conjunction with certain 

 classes in the science faculty of Edinburgh Uni-^ersity. 

 Courses for the diploma of the college and for the science 

 degree of the University are concurrent. A short course, 

 specially arranged to suit those who are actively engaged 

 in farm work, is held at the college annually. The college 

 also maintains a comprehensive scheme of extension work 



