SoS 



NA TURE 



[September 19, 1895 



The meteor was evidently a Perseiil, and had a radiant at 

 36" + 57". It was first seen when at a height of 95 miles above 

 Oxford, and disappeared when 61 miles above Devizes. Its 

 real length of path was 53 miles, and the earth point is indicated 

 in the English Channel about 10 miles south of Lyme Ktajis, 

 Dorsetshire. 



On August :i, ith. 43ni. , Prof. Herschel mapped a small 

 lx)lide, rivalling Jupiter in brightness, and traversing with 

 moderate speed a course of 15" from 229° + 59° to 225° + 44°, 

 or from near 1 Draconis to the head of Boiites. Duration of 

 flight I "5 sec. : the nucleus was evenly bright all the way, and 

 it left a streak for 3 sees. Mr. Corder rcgisleretl the same 

 meteor, and gives the time as ilh. 42m., magnitude equal to 

 Jupiter, and path as 60° + 62i° to "o" + 64° in Camelopardus. 



This object was also a Perseid, the radiant being at 32 + 52° 

 near the cluster at x Persci. The meteor at its first appearance 

 «-as 75 miles high above a point 5 miles N. of Stratford-on- 

 Avon, and at its disap|x;arance 52 miles high over a place 5 

 miles W. X.W. of Great Malvern. Its real length of path was 

 34 miles, and earth point 6 miles S. E. of .\l)erdare. 



Red Spot on Jupiter. — When twilight became too strong for 

 comet-seeking on the morning of August 25 last, I turned my 

 10-inch reflector on Jupiter and saw the red s|xjt, indefinitely, 

 near its central transit. The planet had only just risen alxjve 

 the tops of some houses in this locality, and the telescopic image 

 was by no means goo<l, but I estimated the transit of the spot 

 occurred at 4h. 24m. a.m. (.\ugust 24, l6h. 24m.), or about 

 9"4ni. after Mr. Marth's zero meridian. System II., so that the 

 longitude of the sjxjt was S°"7. The shouldering of the great 

 south equatorial belt, east of the spot, was very conspicuous, and 

 afTorded an excellent guide to the position of the latter. A few 

 minutes after the transit of the re<l spot I noticed a large white 

 spot on the north side of the north equatorial bell, passing the 

 central meridian. A |X)«er of 312 was used in these obser- 

 vations. \V. I'. IIknmm;. 



Bristol, .September 7. 



Curious Optical Phenomenon. 



The fulliiwing description of an optical iihenomenon, and its 

 probable explanation, may be of interest. It will be observed 

 that a similar exj>erience occurring to one not accustomed to 

 making optical experiments would very probatjiy have caused 

 him to believe that he had seen a ghost. It is therefore of 

 importance psychologically. 



The facts observed were as follows: — At about I A.M., 

 August 26, I went to my tiedroom ; to get to it I had to 

 (Mss through a small room which I used as a study. On 

 entering it, though it w.as dark, and I had no lamp, the small 

 r(K>m seemed brightly illuminated, about as bright .as an 8 c.p. 

 lamp would make it, apparently. To one side of a window in 

 the room I saw a man standing, whom I recognised to be myself. 

 The whole impression was very vivid and clear. 



So far nr)thing was oliscr\ed beyond what is described in the 

 ordinary ghost stor)'. I was much occupied with the considera- 

 tion of a problem at which I had Ix-'en working, and did not at 

 first grasp the full signification of what I saw. On turning my 

 head, the figure disappeared, but on looking towartls the 

 window, through which a very faint line came, the image 

 reappeared. I then noticed that it was apprently standing in a 

 position occupied, as I knew, by a large table. On more close 

 examination, without, however, moxing from the spot where I 

 was standing, I saw that it had change<l, and that it ilid not 

 ap|>ear lo have features ; then it ap|K-ared to he flat againsf the 

 wall, anil f finally recognised it xs an after-image of a shallow. 

 (Jn my first seeing it, however, it did not have this a|)|H:arance 

 lo me, and I had evidently mentally supplied the features as one 

 often docs to the face of a friend who is seen at a distance 

 which is really loo great lo admit of actual recognition. 



I then got the impression of having seen Ihc shadow before, 

 and on considering the mailer a few seconds, rememljcred that 

 it Wiis jusi l>efore I had slarte<l for my riK>m, I had lieen 

 working in anolher room, endeavouring lo solve a physical 

 proMi TM r.i r.iir r fi-.r hours, and for alxjut half an hour, or 

 I' steadily looking al a lamp (a habit of 



H' I then got up, leaving the lamp lit, 



•1' O) my lied-room .as mentioned atwve, 



' ' my shadow w.xs thrown by the lamp on 



llii: vi.iM jii^i I'. Mn- rigni of the door. The passages were entirely 

 «Urk, and it was not until I entered the room used as a study, 



NO. I 35 I, VOL. 52] 



that the faint light coming through the window and falling on 

 the same spot of the retina that was prenously iKCupied by Ihe 

 image of the dark doorway, stimulated the after-im;ige. 



I may s;\ythat my health w.ts of the best, but that I had been 

 smoking heavily for a few days previously, and the fact had 

 begun to force itself upon me. 



I would es|5ecially remark upon the apparent brightness of 

 the apparition. I had never seen an after-image so bright. On 

 going back lo the room where the lamp was, I proved that the 

 appearance of the shadow thrown as I went out of the room 

 corresiKjnded with that of the im.ige seen, minus of course the 

 features and colour, which had l>een supplied by the 

 imagination. 



In speaking of optical phenomena, I would say that an easy 

 way of showing that the colours seen in Ihe colour-lo]) are due 

 to lack of accommodation, is by taking a piece of red paper 

 or cloth, and turning the top till the inner or outer line matches 

 it exactly. Then, withoul moving or changing the speed of the 

 top, place before the eye a convex glass. The colour on the 

 lop will disappear, but that of the cloth will of course remain. 

 Similar ex|)eriments to those observed with the top can be 

 observed by drawing dark lines on a piece of glass, and waving 

 dark and white ]xiper behind them. K. A. F. 



A Remarkable Flight of Birds. 



The forms of birds flying at a great height and crossing the solar 

 disc, as described by Mr. Bray in your issue of August 29, have 

 been rather frequently seen here during the spring and autumn 

 months, and the writer has always attributed such flights lo 

 migrating birds on passage. They have usually been noticed 

 while observing the image of the sun projected on a card screen 

 from Ihe eyepiece of a small equatorial telescope ; occasionally, 

 however, ihey have atlracled allenlion at night also, crossing 

 the disc of the moon, upon which iheir forms are very clearly 

 defined, and wiih careful focussing (which is very nearly the 

 same as for parallel rays) it has almost been possililc to identify 

 the si>ecies from the shape of the wings and manner of flight ; 

 birds of Ihe swallow tribe, in particular, have lieen clearly dis- 

 tinguished, and others resembling ihe thrush, possibly redwings 

 or fieldferes, have been noticed. The direction of (light, accord- 

 ing lo the writer's experience, is nearly alw.ays towards the 

 south in .\ugust and .September, and the reverse in .Vpril. 



On August 31, a continuous watch was kept i>n ihe moon 

 from 8.50 to 9.35 r. M., using a power of So diameters on 

 a reflector of 10 feet focus. Only eight liirds were seen, how- 

 ever, four of them slowly crossing from north lo soulh, the 

 other two from west to east (nearly). They were evidently very 

 distant. Kn estimate of the change of focus required for the 

 ap|xirenlly nearest bird gave "15 inch. This would imply a dis- 

 tance of 7900 feet from the telescope, and the moons altitude 

 being about 14' Ihe vertical height of this bird would be 7900 X 

 .sine 14° = 1900 feet (about). Some of the birds, judging from 

 iheir apparent size, must have been two or three times more 

 distant, and therefore higher in the same proportion. 



It would l)e very interesting to obtain systematic observations 

 of such flights of birds from various localities during the 

 migrating seasons. Possessors of telescopes would fiiul these 

 observations a good exercise in that kind of patience or endurance 

 which is so necessary in observing, for instance, a so-called 

 meteor shower al its maximum ! 



The writer would be glad lo receive notes on the subject from 

 those of your rcailers who may care to watch for birds during 

 the aulunm. Estimates of the angle subtended by the spread 

 wings would perhaps give the most reliable means of ascertain- 

 ing Ihc height of ihe birds, and iheir direction of flight can 

 easily be obtained by reference lo the diurnal motion of the sun 

 or moon. It is hoijcd that by collecting data of this kind some 

 new facts may \k learned regarding the mysterious habils of our 

 bird visitors. J. Evershkd. 



Kcniey, Surrey. 



THE WOBl'RN EXPERIMENTAL FRUIT 

 FARM. 



ON June 12 last a small party of those interested in 

 agriculture and horlitulturc, including Mr. Herbert 

 (lardncr, Sir John Thorold, Prof. .Armstrong, Prof. 

 Warington, Dr. X'oclcker, -Mr. Charles Howard, .Mr 



