I40 



NATURE 



[June 7, 1894 



To test the optical photographic distortion up to considerable 

 distances from the centre, seven plates with the Pleiades photo- 

 graphed in the four corners have been measured. It appears 

 that the distortion is practically insensible up to 60' from the 

 centre, and is still small up to So', but is not quite the same in 

 the four corners of the plate. On examination, the character of 

 the images in the four corners was also found to vary slightly, 

 the coma being slightly inwards in one corner and outwards in 

 another. The perpendicularity of the plate and object glass to 

 the optic axis were examined and found to be satisfactory. 



Solar Observatio.vs. 

 Observations of the sun have shown that the solar activity was 

 fully maintained throughout the whole of 1893, the mean daily 

 spotted area for the year being considerably in excess of that for 

 1S92. Thegreat spot of 1892 February still remains the largest 

 hitherto seen in the present cycle, but in 1S93 .\ugust a very 

 fine group attained dimensions but little inferior, and the groups 

 of 1S93 November and 1894 February were very large. The 

 characteristic of the year was, however, rather the great number 

 of groups visible at the same time than the extent of any one of 

 them. Thus in August and December 1S93 as many as 16 or 

 iS distinct groups of spots were seen on the disk at the sametime. 



Magnetic Observations. 

 The variations of magnetic declination, horizontal force and 

 vertical force, and of earth currenis were registered photo- 

 graphically, and accompanying eye observations of absolute de- 

 clination, horizontal force and dip were made as in former 

 years. The period was one of much less magnetic activity than 

 last year, but there was a large increase occurring in 1894 Feb- 

 ruary, at the time of the great sun-spot. Copies of the magnetic 

 and earth current regisiers during the disturbances of February 

 20- -March I and March 30-.\pril i, have been supplied to -Mr. 

 Preece for discussion in connection with disturbances on the 

 telegraph lines. 



Meteorological Observations. 



Meteorological observations have been made as usual. 

 The reductions show that the mean temperature of the year 

 1893 was 5i°l, being l°6 above the average for the 50 years 

 1841-1S90. 



During the twelve months ending 1S94 .\pril 30, the highest 

 air temperature in the shade exceeded So" on 28 days. It 

 was 91 'o on June 19, 93''o on August 16, 94'''2 on -August 17, 

 and 95'! on August iS. In the 53 years since 1S41 higher 

 temperatures have been recorded only mice previously (on both 

 occasions in July). The lowest was 12'S on January 5, the 

 maximum on that day being only l9°o and the mean daily 

 temperature 15' 9. The mean temperature on .Vugust 18 was 

 79 '6, being the highest mean value recorded in August since 

 1841. The mean temperature of January 5 was lower than 

 any previously recorded since 1841, with two exceptions. The 

 mean monthly temperature was alrave the average in all months 

 excepting September, November, and January 1S94. In May 

 it was 4-6, m August 3°'9, in .March 2°7, and in April 3'-8, 

 above the average. In November it svas l°'5 below the average. , 



The number of hours of bright sunshine recorded during 

 1893 by the Campbell-Stokes sunshine instrument was 1454, 

 the greatest number on record since the commencement of the 

 registration in 1877. This is 171 hours above the average of 

 the preceding 16 years, after allowance is made for the small 

 difTerence of indication of the Campbell and Campbell-Stokes 

 instruments. The aggregaie number of hours during which 

 the sun was above the horizon was 4454, so that the mean 

 proportiin of sunshine for the year was 0'326, constant sun- 

 shine being represented by I. 



The rainfall for 1893 w.a5 201 inches, being 4'4 inches below 

 the average of the 50 years 1841-1890. From .March I to 

 September 30 (the period of the great drought) the rainfall 

 amouDted to only 777 inches, while the average for the 50 

 years 1841-90 for those months is I4'22 inches. 



The mean amount of clouil for the year on the scale o- 10 

 was 5 75. The average amount as determined by Mr. Kills 

 (Quarlerly Journal Roynl AfeUorohgUal Socitty, vol. xiv.) 

 from 70 years' observations is 6 75. 



The outlook as regards instruments and accommodation for 1 

 Ihem is staled to be fairly satisfactory ; but the fact that four 

 vacancies in a staff of twelve persons have occurred during the 

 fiscal year has ncce<isarily caused serious disorganisation of the 

 work, and greally handicaps progress. I 



NO. 1284. VOL. 50] 



SCIENCE IN THE MAGAZINES. 



T 



MERE are few articles of scientific import in the magazines 

 received by us. By this we do not mean to say that science 

 is unrepresented in magazine literature for June, but that the 

 articles, while afTording an excellent pabulum for the omnivorous 

 reader, lack originality of thought. They are, in fact, more 

 descriptive than suggcslive. "In the year 1887" (writes Mr. 

 Edison, as an introductory note to an arlicle by Antonia and \V. 

 K. L. Dickson in the Ceutuiy) " the idea occurred to me that 

 it was po-sible to devise an instrument which should do for the 

 eye what the phonograph does for the ear, and that by a com- 

 bination of the two all motion and sound could he recorded and 

 reproduced simultaneously. " The development of this idea, 

 and its practical realisation, are well described by the authors 

 of the arlicle on Edison's kineto phonograph — this being the 

 comprehensive term given to the invention that is able to record 

 and give back the impressions to the eye as well .is to the ear, 

 Muybridge, Marey, boys, and others have shown what can be 

 done in the way of instanianeous photography, but the plan 

 used by Edison to obtain pictures of movable objects appears to 

 dilTer from any previously used, .\fter many trials, a highly 

 sen-itised strip of celluloid one and a-half inches wide has been 

 adopted for the production of negatives, each strip being per- 

 forated on the outer edge. " The»e perforations occur at close 

 and regular intervals, in order to enable the teeth of a locking- 

 device to hold the film steady in the nine-tenths of the one 

 forty-sixth part of a second, when a shutter opens rapidly and 

 admits a beam of light, causing an image of phase in the movr 

 ment of the subject. The film is then jerked forward in !t- 

 remaining one-tenth of the forty-s xlh part of a second, .-.11 , 

 held at rest while the shutter has again made its round, ;i<l 

 milling another circle of light, and so on until forty-six inlpI^■^ 

 sions are taken a second, or 2760 a minute. This speed yicl 

 165,600 pictures in an hour, an amount amply sufiicient for 

 evening's entertainment, when unreeled before the eye. . . 

 The advantage of this system over a continuous band, and o( .1 

 slotted shutter forging widely ahead of the film, wouM be thi-. 

 that in one case only the fractional degree of light comprise i 

 in the I720lhpart of a second is allowed to penetiate to 1 he film, 

 at a complete sacrifice of all detail, whereas in the present system 

 of stopping and starling, each picture gets one-hundrelth p.ii: 

 of a second's exposure with a lens but slightly stopped down 

 time amply sufficient, as any photograper knows, for the atl.n 

 ment of excellent detail even in an ordinarily good light." The 

 perforations in the film, referred to in ihe loregoing, arc -I 

 assistance in establishing harmonious relations between tlu- 

 kineloscope and phonograph, in making ihe action recordt 1 

 by the one suit the word imprinted upon the other. Sever 

 reproductions of series of pictures obtained by the kinetogr.i] 

 accompany the article. In order ihal the subjects leaving tlii 

 ** passing moods" upon the kinetograph film may be brillianiiy 

 illuminated, a new kind of studio h.as been con>trucied. The 

 building is pivoted at the centre, and is capable of being rolair ! 

 .so as to present any desiied aspect to the sun. Another arti. 

 in the Cenlury, entitled " Field Notes," by Mr. John linrrough 

 contains some interesting notes on the habits of a few comtn 

 animals. This kind of contribution is very common in 1 

 magazines. " The Dog," by Mr N. S. Shaler, and " American 

 Game Fishes," by Mr. L. M. Vale, both in Scritmer, belong to 

 this anecdotal class. 



Casiclfs Family Magazine contains an article by Mr. 

 Munro on " How I discovered the Norlh Pole." The story 

 of course, purely im.aginary, but the idea upon which 11 i^ 

 based might be developed lor preliminary geographical explm.i- 

 lion. A number of balloons are supposed to have been set fnc 

 in high norlh latitudes, each provided with magazine camti.i~ 

 stocked wiih plates and having long-dislancc lenses of varn"' 

 focal lengths. Exposures were automatically made at regul 

 intervals by means of clockwork, so ilial when ihe ballu 1 

 were caplured, they contained phoiogiaphs of the tracks abn\' 

 which they had passed. Each balloon also carried a gyrosco] i 

 mounted in such a manner that when ils axis of roiation becanu- 

 vertical — that is, when the balloon containing 11 was exactly 

 over the Norlh Pole, camer.is were brought into action and 

 photographs taken of the carlh below. 



" The Spring of I be Year," \n/.on!;maii's, is an inspiring arlicle 

 written by Kichard Jeflerics, and found byMrs. Jtffcries amum; 

 ihe MSS. left by him. Mr. A. Morgan retails some seconl 

 hand information on "Celestial Pholograjihy " in the same 



