August 27, 1903] 



NATURE 



389 



A. Naturalist's Calendar, kept at Swaffham Bulbeck, 

 Cambridgeshire, by Leonard Blomefield {formerly 

 Jenyns). Edited by F. Darwin. Pp. xix + 85. 

 (Cambridge : University Press, 1903.) 

 In his introduction the editor has given several reasons 

 (all of them excellent in their way) for the reissue of 

 this excellent memorial of an e.xceedingly accurate 

 and gifted naturalist. He has apparently omitted, 

 however, that which, in our opinion, is the most im- 

 portant argument of all, namely, the relatively early 

 date (previous to 1846) at which the record was kept. 

 This renders it extremely valuable for comparison 

 with observations of a similar nature made at the 

 present day, for the purpose of ascertaining whether 

 any secular changes in the date of the arrival of 

 migratory birds or in the flowering of plants has 

 taken place in this country since the compilation of 

 this calendar. Whether any such differences do occur 

 would require very careful comparison, but we should 

 not be surprised to learn that the average date of the 

 cuckoo's arrival has altered somewhat since Blome- 

 field's time. Be this as it may, the well-known 

 scrupulous accuracy of its compiler renders his 

 calendar of natrure a record of exceptional value and 

 interest, bel6n]g'ing to a period when such compilations 

 were rare. There is, therefore, every justification for 

 its republication in the present convenient form, and 

 its appearance at a morphological centre like Cam- 

 bridge may certainly be regarded as a good augury 

 for the future of natural history studies. 



Mr. Darwin gives several anecdotes of the author, 

 to which the present writer can add another. Mr. 

 Jenyns (as he was then called), who was by no means 

 a handsome man, was in early life accustomed to 

 preach occasionally in a church attended by the 

 Henslow family. After one of these periodical visits, 

 the younger members of the family were asked why 

 they were always so unusually quiet in church when 

 Uncle Leonard preached. To which query came the 

 reply that " he kept on making such ugly faces." 



Elements of Physics, Experimental and Descriptive. 



By An1t)s T, Fisher, B.Sc, assisted bv Melvin J. 



Patterson, B.Sc. Pp. 184. (London : D. C. Heath 



and Co., 1903.) Price 25. 6d. 

 Those of us who are engaged in university teaching 

 are personally interested also in the kind of science 

 teaching which is given in schools. Lads come to 

 college fresh from school crammed with what is called 

 physics ; but, owing to its unsatisfactory character, 

 our first effort is usually to knock out of them the loose 

 and erroneous knowledge w^ith which they have been 

 crammed. We are afraid that the book under review 

 is not likely to improve matters. A long list of errors 

 which we have noted down lies before us — far too 

 long to reproduce here — and we must be content with 

 a few as a sample. 



The diagrams of lines of magnetic force of currents 

 (p 131), of the dispersion in a prism (p. 96), of the 

 iormation of a rainbow (p. 98), are all wrong. It is 

 incorrect to state that the image of (sic) a concave lens 

 is always smaller than the object, and that a concave 

 meniscus is a converging lens. The field of a magnet 

 does not vary 'as the inverse square of the distance. 

 An induced charge is not usually equal to the inducing 

 charge. 



A paint-brush illustration of the production of in- 

 duced currents (p. 137) gives the wrong direction to 

 th':? current. The conservation of energy is stated to 

 be a consequence of the conservation of mass ! 



In spite of numerous errors and fallacies, and weak- 

 nesses of description, the book is not wholly bad; but 

 what a burden is thrown upon the teacher who has to 

 put all' these wrong things right ! For the private 

 student the book cannot be recommended. 



NO. 1765, VOL. 68] 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



An Earthquake Shock at Kimberley. 

 Local earthquakes are rare phenomena here. There 

 was, however, a small shock at 8h. 43m. p.m. (G.M.T.) on 

 Friday last, July 31. It was accompanied by the loud 

 rumbling noise resembling the passing of a heavy waggon, 

 and caused some shaking of furniture. It appears to have 

 been felt and heard over a considerable area. The record 

 by my large horizontal pendulum showed a single nearly 

 sudden dip to the west of 3-6mm. (t.e. from 3o-4mm. to 

 340mm., measured from the reference base-line), roughly 

 corresponding to a tilt of about 3*, and a rather more 

 gradual recovery, with very little (if any) return swing to 

 the east. No certain signs of preliminary tremors could 

 be detected upon the record. It seems important (c/. Milne, 

 " Earthquakes," p. 309, 4th ed., 1898) that for some days 

 previously there had been a gradual, general dip of the 

 level to the east, the mean distances of the hourly readings 

 from the reference base-line, measured from east to west, 

 being : — 



July 27 34'3 mm. 



„ 28 34-0 ,, 



n 29 311 „ 



,, 30 270 „ 



,, 31 28-1 „ 



Aug. I 29*0 „ 



The weather during the week had been moderately warm 

 and cloudy, but, so far as I know, there was not any rain 

 anywhere on the table-land. There was no disturbance of 

 the barometer accompanying the shock. 



I enclose a cutting from the Diamond Fields Advertiser 

 of August 3. It gives the duration at Koffyfontein as three 

 minutes, which probably really means that some loose 

 articles of furniture might have remained swinging for 

 some time after the shock had passed. KofTyfontein, how- 

 ever, like Kimberley, is a diamond mining centre, and from 

 various reports it seems to be demonstrated that the earth- 

 movement was much more pronounced in the vicinity of 

 the open workings than elsewhere. J. R. Sutton. 



Kenilworth, Kimberley, S. Africa, August 3. 



Sun-spots and Phenologfy, 



It can be shown in several ways, I think, that we have, 

 on the whole, in these parts (London), more warmth when 

 the sun-spots are numerous than when they are few, a 

 state of things rather opposite to that in the tropics, 

 where (according to M. Nordmann, who has lately con- 

 firmed the work of Dr. Koppen some thirty years ago) 

 sun-spots mean coolness, and there is most warmth about 

 minima. 



The recurring contrast, in the case of Greenwich, appears 

 to be most distinct in the early part of the year. Thus 

 we may show it by taking the mean temperature of 

 P'ebruary and March, and smoothing the curve with 

 averages of five (curve A in diagram). B is the sun-spot 

 curve. Thus about sun-spot maxima, the milder weather 

 of spring seems to set in, on an average, earlier than at 

 other times. It might be expected that this would have 

 an influence on the data of phenology (time of flowering 

 of plants, &c.), and in many cases we find it is so, that is, 

 curves which represent the dates of flowering of plants 

 will be found to show a certain agreement with the 

 temperature curve of February-March, and with the sun- 

 spot curve. 



In the diagram are given two of these phenological curves 

 (C and D). C is that for flowering of Kibes sanguineum 

 in Edinburgh (1850-87), and D that for flowering of 

 .'Isalea pontica at Pare de Baleine, Allier, in the heart of 

 France (1858-1901). (The scales are separate.) 



The date of flowering is given as the day-number in the 

 year, and these numbers are smoothed with averages of 



