December 6, 1900] 



NATURE 



M5 



and zinc ; these waves are particularly interesting, as it would be 

 practically impossible to obtain them by the "point-to-point" 

 method, since arcs between carbon and metals burn very un- 

 steadily. The arc, it will be seen, only burns for half a period ; 

 when the metal is positive (upper curves) the current is able to 

 flow, and the P. D. and current curves have the shape char- 

 acteristic of the same curves for the carbon arc, only some- 

 what accentuated ; for the other half period, when the metal 

 is negative no current flows at all, and the current curve is 

 flat along the zero line, the P.D. curve being, in consequence, 

 that given by the dynamo on open circuit. The three curves are 

 for a frequency of lOO periods per second. Curve 4 shows the 

 P.D. and current through the primary of an induction-coil in 

 which the contact-maker was driven by a motor, no condenser 

 being used. The steady growth of the current and its rapid 

 fall at break can ba clearly observed in the current curve. 

 From the P.D. curve it will be seen that the P.D. at the start 

 is high, since, until the current begins to flow, the P.D. between 



/""■\ 



\—PD. dynamo // \ 



Curve N^3. 





Current 



Curve fil?4. 



Fig. 7. 

 Data for Curves in Fig. 7. 



the terminals of the coil is equal to the E.M.F. of the cells. 

 As the current rises, the P.D. between the terminals of the coil 

 falls, due to the drop in volts in the circuit outside the coil ; 

 finally the break occurs and there is a large kick of the P.D. 

 in the opposite direction to that applied. 



From what has been said some idea will be gathered of the 

 great value of the instrument that has been put into our hands 

 by the invention of the oscillograph. To the scientific investiga- 

 tor it opens wide fields for experimental research, and it will en- 

 able the engineer to know more about the currents and E.M.F.'s 

 with which he works. In addition, the projection oscillograph 

 should prove invaluable for lecture and demonstration purposes, 

 for even the simplest problems of alternate current working are 

 by no means easy of comprehension by the average electrical 

 student, who approaches them with only a bowing acquaintance 

 with differential calculus and Fourier's theorem. The remark- 

 able clearness with which their working can be demonstrated on 

 the screen by the oscillograph will go a long way to give 

 students a clear idea of their properties. 



NO. 1623, VOL. 63] 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Oxford.— Mr. T. Loveday, of Magdalen College, has been 

 elected John Locke Scholar for the ensuing year. 



Mr. G. C. Bourne has been re appointed a delegate for the 

 extension of University teaching. 



The electors to the Wykeham Professorship of Physics have 

 appointed Mr. J. S. Townsend, Fellow of Trinity College, 

 Cambridge, and Demonstrator in the Cavendish Laboratory. 



Cambridge. — The Clerk Maxwell Scholarship in physics is 

 vacant through the election of Mr. J. S. Townsend to a professor- 

 ship at Oxford. Candidates are to apply to Prof. J. J. Thomson 

 by December 18. 



The British Westinghouse Electric Company have presented to 

 the Engineering Laboratory a valuable dynamo and other appara- 

 tus illustrating the generation and use of polyphase currents. 



An opportunity for seeing the North- 

 ampton Institute, Clerkenwell, and ex- 

 amining some of the work done in 

 the laboratories, will be afforded to- 

 morrow evening (December 7), when 

 the annual prize distribution and mem- 

 bers' and students' conversazione will 

 be held. Sir John A. Cockburn,. 

 K.C.M.G., will distribute the prizes. 



In an important article by Dr., 

 William Wallace in the current number 

 of the Fortnightly Keview, on 'the- 

 Scottish University crisis," attention is 

 drawn to the urgent need there is for a. . 

 greatly increased expenditure upon 

 Scottish universities if they are ta - 

 maintain the reputation they have en- 

 joyed in times gone by. It is urgedi 

 that a lump sum of not less thar* , 

 1,500,000/. IS required to place all the 

 Scottish universities in such a position 

 that their degrees should be regarded 

 as of equal value with those of England, 

 Germany, or even Annerica. Such 

 money is regarded as imperatively 

 necessary for the following main pur- 

 poses : (i) The conversion of the pre- 

 sent skeleton faculties into real teaching 

 organisations ; (2) For laboratory and 

 other scientific equipment ; (3) ' For 

 libraries; (4) For the endowment of 

 industrial universities or of genuine 

 industrial faculties in the universities; 

 (5) For the endowment of poor under- 

 graduates ; (6) For the endowment of- 

 post-graduate research. 



Dr. Oliver Lodge made some 

 novel suggestions as to the time, place 

 and purpose of University examina- 

 tions, in his address to the students- 

 of the University of Birmingham on- 

 November 28. His proposals amounti 

 essentially to this — that examinations should not immediately 

 follow teaching, and that a vacation interval should intervene for 

 private study and revision, quiet thought, assimilation and diges- 

 tion. ' Students should not be taken straight from a lecture-room 

 into an examination room, so that they might tell the examiner 

 what the professor had said before they had time to forget it. So 

 he wished to urge that a long vacation should be left between 

 instruction and examination ; that the examinations be held in 

 September instead of at the end of June. If no. interval for 

 rumination was afforded during student days, if the unrooted 

 ideas were pulled up for inspection by the examiner at the end 

 of each session, and the student turned loose; in the holiday s» 

 empty, swept and only partially garnished, for a period of com- 

 plete idleness before another filling-in process began, then the 

 last state of that man was liable to be little better than the first. 

 The principle underlying Dr. Lodge's proposals is sound enough, 

 but there are difficulties and objections in the application. What, 

 for instance, is to. prevent the student who, wishes to obtain a good 

 place in the examination at the commencement of the session . 



