November 9, 1893] 



Nu4 rURE 



further allowed to give some reasons for the opinion expressed. 

 That there exists a relation between sun-spots and mat^neti'^m 

 is undoubted. And although those who are able to study the 

 variations of sun-spots side by side with the variations of map;- 

 netism can very well see to what extent the relation definitely 

 holds, it is difficult adequately to convey to others a due im- 

 pression of all the circumstances of the case. Periods of maxi- 

 mum sun-spots are periods of great magnetic activity and 

 energy, whilst periods of minimum sun-spots are periods of 

 magneiic quiet. But it has not yet been found possil)ieto trace 

 direct correspondence in details. Thus, when a large spot is 

 present there may occur one or more considerable magnetic dis- 

 turbances or storms, some enduring it may be for a i&w hours 

 only, others it may be for several days, but, assuming direct 

 solar influence, what it is that precisely determines when such 

 disturbances shall arise is unknown. Further, at times of sun- 

 spots being numerous, there is also considerable general magnetic 

 irregularity. Now, in these magnetic disturbances and irregu- 

 . larities there will be innumerable individual motions far 

 I exceeding in magnitude that accompanying the Carrington sun 

 I outbuist, and yet during all the many years that have elapsed 

 since 1859, through which period the solar surface has been 

 continuously scrutinised by hundreds of observers in different 

 ; lands, no second occurrence similar to that of 1S59 has come to 

 1 light. But if there be so close a connection between solar and 

 ' magnetic phenomena as the occurrence in question would seem 

 to indicate, the fact that we have no corroboration of the 

 solitary observation of 1S59 is surely remarkable, considering 

 j that, of late years, it is very much to correspondence in details 

 I that attention has been to a great extent directed. If irregular 

 magnetic movements were comparatively few, the observation 

 <T 1859 might possess some significance, but they are, on the 

 contrary, multitudinous, many at times occurring during the 

 course of a single day, and often of considerable magnitude, but 

 vet without any recorded accompanying solar manifestation. 

 To sum up, the points of the matter may be thus stated : — 



(1) The solar outburst in l859was seen independently by two 

 observers : the fact of its occurrence seems therefore undoubted. 



(2) The corresponding magnetic movement was small. 



(3) Many greater magnetic movements have since occurred. 



[ (4) No corresponding solar mani.'^estation has been again 

 I seen, although the sun has since been so closely watched. 



The solar outburst of 1859 would thus appear to have been a 

 rare phenomenon, and its observed occurrence at the time of a 

 recorded magnetic movement quite an accidental coincidence. 



This conclusion in no way invalidates the question of general 

 relation between sun-spots and magnetism, whatever may be 

 the true explanation of that relation. 



Greenwich, November 6. William Ellis. 



The Recent Earthquake. 



After the Pembroke earthquakes of August 1892, you were 

 good enough to insert a letter from me (vol. xlvi. p. 401) asking 

 for observations from different places. In reply to this letter, I 

 received so many and such valuable records, that I should be 

 greatly obliged if you would allow me to make a similar request 

 lor accounts of the recent earthquake of November 2, in Wales 

 and the West of England. I should be very grateful for de- 

 scriptions from any place whatever. The questions printed 

 below indicate the points on which information is chiefly desired, 

 but if any observers are able and willing lo give further details, 

 I shall be pleased to send them my fuller list of questions, which 

 I may remark are somewhat different from those given in the 

 letter referred to above. 



(0 Name of the place where the earthquake was observed. 



(2) Time at which it was felt, if possible to the nearest minute, 



(3) Nature of the shock, {a) Were two or more distinct shocks 

 felt, separated by an interval of a few seconds ? (/') If so, which 

 was the stronger? (r) What was the duration (in seconds) of 



' each, and of the interval between them? [d) During this in- 

 terval was any tremulous motion felt or rumbling sound heard ? 



(4) Duration in seconds of the whole shock, not including the 

 accompanying sound. 



(5) Was the shock strong enough {a) to make doors, windows, 

 ! fire-irons, &c., rattle ; {b) to cause the chair, &c. , on which the 

 j observer was resting to be perceptibly raised or moved ; (c) to 



make chandeliers, pictures, &c. swing, or to stop clocks ? 



(6) (a) Was the shock accompanied by any unusual rumbling 

 sound, and, if so, what did it resemble ? [b) Did the beginning 

 of the sound precede, coincide with, or follow the beginning of 



NO. 1254, VOL. 49] 



the shock, and by how many seconds? (c) Did the end of the 

 sound precede, coincide with, or follow the end of the shock, 

 and by how many seconds? ((/) Were the strongest vilirations 

 felt before, at, or after the instant when the sound was loudesi, 

 and by how many seconds? Chaklks Davison. 



373 Gillott Road, Birmingham, November 6. 



"An Ornithological Retrospect." 



1 HAVE been interested in leadinc "An Ornithological 

 Retrospect," by your correspondent, Dr. Sharpe. His refer- 

 ence to myself by name in the concluding paragraph is partly 

 my excuse for troubling you with a few remarks upon this 

 article. Dr. Sharpe, in one long breath, deplores (pleonastically) 

 the fact that "very little anatomical work has scarcely been 

 done" recently in orniiholopy, and exults over a reviewer in a 

 "leading London paper," who apparently took the same view 

 — tomahawking him with the remark that " in every branch of 

 the subject considerable progress has been made. ' I think that 

 the opinion of the minority in this case is correct, and that our 

 knowledge of bird anatomy is progressing. But those of us who- 

 are occupied with this study have frequently lo regret the ignor- 

 ing of anatomical facts by systematists ; this is particularly dis- 

 couraging, since by far the larger proporiion of papers upon 

 bird anatomy are purely of systematic inierest, dealing 

 with the resemblances between bird and bird. Dr. Sharpe 

 evidently feels that the British Museum Catalogues of Birds are 

 not beyond criticism from this point of view. In one or two- 

 volumes there is a conspicuous absence of any arrangement in 

 accordance with anatomical fact. Dr. Sharpe, therefore, is 

 rather imprudently candid in saying that to understand these 

 catalogues a man must be an ornithologist. 



Zoological Society's Gardens. Fkank E. Beddard. 



The Foam Theory of Protoplasm. 

 In your issue of October 19 there appeared, under the title 

 " Biitschli's Artificial Amcebre," a review, by Dr. John Berry 

 Haycraft, of Prof. Biitschli's work upon protoplasm. I venture 

 to think that in manv ilaces Dr. Haycraft has misrepresented 

 entirely Prof. Biitschli's researches, while other objections or 

 criticisms which he brings forward are answered in the book 

 itself. Since I have been engaged for some time upon a trans- 

 lation of Prof. Biitschli's work, which is now in the press, I 

 must ask your readers to suspend their judgment until they have 

 a belter opportunity of forming an opinion for themselves. 



2 Blackball Road, Oxford. E. A. Minchin. 



SCIENCE IN THE MAGAZINES. 



AMONG the magazines received by us, the Fo7-t- 

 nightly is well to the front as regards articles 

 having a scientific interest. Dr. Alfred R. Wallace 

 writes on "The Ice Age and its Work," with the object 

 of explaining " the nature and amount of the converging 

 evidence demonstrating the existence of enormous ice- 

 sheets in the northern hemisphere, to serve as a basis 

 for the discussion of the glacial origin of lake-basins^ 

 which will form the subject of another article." After briefly 

 describing the foundation of the science dealing with 

 glaciers and their action, and the early school of glacial- 

 ists, Dr. Wallace states the phenomena which points to 

 the former existence of glaciers in regions where the 

 mountain-tops are at present below the snow-line. These 

 are classified as follows : — (]) Moraines and drifts; (2) 

 Rounded, smoothed or planed rocks ; (3) Stride, grooves, 

 and furrows on rock- surfaces ; (4) Erratic and perched 

 blocks. As a good example of a moraine, that in Cwm 

 Glas, on the north side of Snowdon, is mentioned, 

 together with those in Glen Isla (Forfarshire), and the 

 Troutbeck alley near W^indermere. In Cwm Glas, also, 

 smoothed and rounded rocks are to be seen above the 

 moraine. Striated, grooved, and fluted rocks are exem- 

 plified by those near the lakes of Llanberis, and by the 

 remarkable effects exhibited at Kelly's Island, at the 

 western end of Lake Erie. The enormous block near St. 

 Petersburg, and the mass of Swedish red granite found 

 at Furstenwalde, south-east of Berlin, are given as in- 



