Dec 20, 1883] 



NA TURE 



1S3 



counts for no trace of it being found, though the wave coming 

 from the eastward on the morning of that day, just before the 

 cyclone had arrived. No. VII., was discernible. . 



" There is no definite statement, io far as I am informed 

 at present, of tlie true time of any particularly severe shock 

 IT explosion at Krakatoa excepting that whieli is contained in 

 the letter of Mr. Watson (published in Nature, December 6, 

 1S83), whose ship was within a few miles of the volcano on the 

 morning of August 27. He refers to an unusually severe explo- 

 sion as having occurred at llh. 15m. a.m. local time, which is 

 nearly 45 minutes later than the time, gh. 32m., arrived at 

 in the foregoing discussion. The point of the disturbance (as 

 iiidicated by the barograms) which has been taken as the front 

 of the wave is the highest point of the first abrupt rise of the 

 trace, and is perhaps, on an average, not far from one hour after 

 the first signs of disturbance, the increase of pressure having 

 been very rapid during the interval, but broken into two or three 

 steps or oscillations. During the following half hour there is 

 Usually a large decrease of pressure, succeeded by another abrupt 

 rise lasting about half an hour. Then follow a fall of about an 

 hour, then a rise of an hour and a half, and then a fall of an 

 hour and a quarter. The whole length of the disturbance on 

 ihe time scale is between five .and six hours, corresponding to an 

 actual distance of between 3500 miles and 4000 miles. The 

 length of the first main wave of the disturbance is about one 

 hvur on the lime scale, or about 700 miles in length over tlie 

 earth's surface. 



"In the present position of our knowledge of the facts, it 

 can only be surmi-ed that the shock of iih. 15m. a.m. of 

 August 27, oLserved by Mr. Watson, corresponds to the second 

 main feature of the disturbance. That the wave which forms 

 the first feature would have originated at lih. 15m. a.m. is 

 apparently incon^istent with the observed velocities, which it 

 has been shown are remarkably consistent, and indicate without 

 much doubt an origin at gh. 32m. a.m. 



**The barometric disturbance at Mauritius noted by Dr.Meldrum 

 is said to have begun soon after II a.m. local time. The dis- 

 tance from the volcano to Mauritius being about 3450 miles, 

 the wave at the rate of 674 miles per hour would have reached 

 the island in 5h. 7m. Taking the great shock at 2h. 32in. 

 Greenwich mean lime, as before reckoned, the wave would 

 reach Mauritius at 7h. 39m. Greenwich me.an time, or adding 

 the .allowance for difference of longitude, 3h. 50m., the local 

 time would be llh. 29m., which agrees satisfactorily with the 

 facts as recorded. 



" In conclusion, it may be noticed that the sea-waves produced 

 by this volcanic disturbance, assuming the time of its occurrence 

 to have been 2h. 32m. Greenwich mean time on August 

 27, vere propagated with an approximate velocity of 4S0 

 miles an hour to Mauritius, of 430 miles an hour to Port 

 Elizabeth near the Cape of Good Hope, and 420 miles to Galle, 

 and a somewhat slow'er rate to Aden. The details of the occur- 

 rence of these waves on the coasts of India will shortly be laid 

 before the Society by Major Baird, who has informed me that 

 the velocity of the wave between Galle and Aden was 378 

 miles an hour, and the lengths of the great waves from 2iS7 

 to 630 miles." 



"P.S. — December 15. Since the above was read before the 

 Royal Society a copy of the barometric trace from New York 

 has been received, which shows disturbances very similar to 

 those recorded at Toronto, and at times which are quite in 

 accordance with the general conclusions stated in the paper." 



NOTES 



In connection with the resignation of Prof. Sylvester of his 

 Chair in the Johns Hopkins University, we find that it 

 was resolved at a meeting of the trustees held October i, 

 "That as thi-i resignation is doubtless the result of mature 

 reflection on the part of Prof. Sylvester, it is hereby accepted, 

 but that in doing so the Board of Trustees cordially extend to 

 him its hearty thanks for the invaluable services which he has 

 rendered to the University, and also its profound sense of the 

 great ability, the conscientious fidelity, and untiring energy with 

 which he has discharged the arduous duties of his Chair, thereby 

 elevating the science of mathematics to its proper plane, not only 

 in this [institution but in this country." It was also resolved 



"That Prof. Sylvester be appointed Professor Emeritus in the 

 ■"■ohns Hopkins University." 



It may be remembered that at the recent Geodetic Congress 

 the French delegates opposed the adoption of Greenwich as the 

 universal meridian, though M. Faye was in favour of the adop- 

 tion of Greenwich time. At the meeting of the Paris Academy 

 on December 3, M. Faye, whilst supporting the proposal that 

 the universal time should be that of Greenwich, stipulates for the 

 civil hour instead of the astronomical hour, and for the counting of 

 longitudes from oh. to I2h. positive towards the east and negative 

 towards the west, instead of from oh. to 24h. reckoned towards 

 the east, but leaving it to astronomers and navigators to employ 

 at discretion for the universal time that according to civil or 

 astronomical reckoning, as may seem best. 



A MEETING was held in Sheffield last weekjfor the purpose of 

 carrying out, in connection with Firth College, a proposed 

 technical department having reference to the trade of the district. 

 Among those who spoke were Mr. Mundella and Dr. Sorby, and 

 we need not say that all agreed as to the desirability of establish- 

 ing such a department, and the necessity of educating our cap- 

 tains, as well as our privates, of industry, in the principles of 

 their crafts. For that, Mr. Mundella insisted, is the true 

 technical education. He gave the experience of a friend who 

 has just been visiting the United States, and inspected the means 

 for technical education existing there ; the distinct conclusion 

 was "that there is more skill and intelligence in American 

 industrial pursuits than there is in our English industrial pur- 

 suits." It is much that we know our weakness and are taking 

 means to remedy it. No doubt the Firth College will soon have 

 a well equipped technical department. 



The Lecture Arrangements at the Royal Institution before 

 Easter, 1S84, are as follows :— Prof. Dewai-, six lectures (adapted 

 to a juvenile auditory) on Alchemy (in relation to modern science), 

 commencing on Thursday next (December 27) ; Mr. R. S. Poole, 

 two lectures on the Interest and Usefulness of the Study of Coins 

 and Medals ; Mr. A. Geikie, five lectures on the Origin of the 

 Scenery of the British Isles ; Prof. J. G. McKendrick, five lec- 

 tures on Animal Heat : its Origin, Distribution, and Regulation ; 

 Prof. Ernst Pauer, six lectures on the History and Development 

 of the iSIusic for the Pianoforte, and its Predecessors the Clave- 

 cin, Harpsichord, &c. ; Prof. Tyndall, six lectures on the Older 

 Electricity, its Phenomena and Investigators ; Prof. Henry 

 Morley, six lectures on Life and Literature under Charles I. ; 

 and Capt. Abney, six lectures on Photographic Action, con- 

 sidered as the Work of Radiation. The Friday Evening Meet- 

 ings begin on January 18, Prof. Tyndall on Rainbows. The 

 discourses on tlie other evenings will probably be as follows : — 

 Rev. T. G. Bonney, the Building of the Alps ; Prof. Ma 

 MUUer, Rajah Rammohun Roy ; Mr. G. J. Romanes, the Dar- 

 winian Theory of Instinct ; Prof. Thorpe, the Chemical Work 

 of Wohler; Sir Frederick Bramwell, Loudon (below bridge) 

 North and South Communication ; Prof. Hughes, Theory of 

 Magnetism (illustrated by experiments) ; Mr. C. V. Boys, 

 Bicycles and Tricycles in Theory and Practice ; Mr. J. N. 

 Langley, the Physiological Aspect of Mesmerism ; Mr. Walter 

 Besant, the Art of Fiction ; Prof. O. Reynolds, the Two 

 Manners of Motion of Water (shown by experiments). 



Every one must wish well to the scheme for an Institute for 

 East London, to the meeting in connection with which last 

 Friday at the Mansion House the Pre.-ident of the Royal Society 

 gave the benefit of his experience as an East End doctor forty 

 years ago. The demand for such commodities as the Institute 

 would furnish is strong enough ; eminent men of science who 

 have lectured ic Whitechapel on their special subjects tell us 



