i 9 4 



NA TURE 



\_June 26, 1884 



large circle of readers — kindly sent me an account of her expe- 

 rience of the offensive use of the Cuvierian organs. She tells 

 me that in the Bay of Rapallo at Santa Margherita, near Porto 

 Fino, she dredged a large black Holothurian, and that " the 

 tangled mass of white threads you mention is so sticky and in 

 such quantity that, after having taken one of these animals out 

 with my hand, I had considerable difficulty in freeing my fingers 

 from the threads ; indeed, my hand was not comfortable till I 

 had washed it in hot water." On the other hand, an inquiry 

 made of a gentleman living at Penzance, and interested in Echi- 

 noderms, resulted in the answer that he had never heard of the 

 "Cotton-Spinner." F. Jeffrey Bell 



The Red Glow 



In your issue of April 10 (p. 549) is the statement by an 

 observer in Australia that the " red glow was margined by an 

 immense black bow stretching across from north-west to south- 

 east." 



I wish to say that the above language almost exactly describes 

 the appearance to which I alluded on the same page as " the earth 

 shadow cutting off the upper rim of the first glow. " The " black 

 bow " of the Australian was evidently the shadow of the horizon 

 projected on the haze stratum. In both the above cases the 

 lower surface of the haze was evidently well defined, so that as 

 the horizon intercepted the direct rays of the sun, a well-marked 

 shadow moved westward and downward. Above this black rim 

 or bow appeared the secondary glow, produced by the reflection 

 of the sun's rays from that portion of the haze surface which was 

 directly illuminated. Very often the second glow was more 

 conspicuous and impressive than the first, because it shone 

 against the dark sky of night. 



In the Proceedings of some association I have just read an 

 astonishing estimate of the height of the haze as 141 miles, based 

 on the fact that it received the sun's rays one houraftei sunset, 

 the fact being strangely overlooked that the late reflection was a 

 secondary one. 



One evening the shadow or "black bow" was beautifully 

 indented or serrated, doubtless by the shadows of remote cumuli 

 such as are commonly seen in platoons on our evening horizons. 

 The "black bow " was seen only during the first few days of the 

 glows in September. S. E. BISHOP 



Hawaiian Government Survey, Honolulu, May 20 



P.S. — I hoped long ere this to have sent you data from the 

 Caroline Islands received per Morning Star, now much overdue. 

 We fear she has suffered disaster. 



Light Phenomenon 



This evening towards sunset, at 7.55 p.m., there was a 

 column of light extending from the upper part of the setting sun 

 to about 20°, the column being truncated and perpendicular 

 to the horizon. After remaining thus for about two minutes, 

 the sides of the pillar lost somewhat of their perpendicularity, 

 and, with the whole volume of the sun, put on prismatic colour- 

 ing, the ray (a single one. and still truncated) at times appearing 

 to be a wave of flame. I observed this, with four or five other 

 persons, from the cliffs, and should like to know if the peculiarity 

 of this sunset was observed by others. It continued until S. 20 

 p.m., when the sun was below the horizon, and the wave of 

 flame ceased. I can hardly better describe this ray than as being 

 very like a northern light, only extremely circumscribed in size, 

 and intensely brilliant. R. D. Gibney 



Falmouth, June 21 



Atmospheric Dust 

 In connection with the recent experiments of Dr. Lodge and 

 Mr. John Aitken (described in late numbers of Nature) on the 

 filtration of dusty atmospheres, I have ventured to call your atten- 

 tion to the following, as of possible interest. I have had frequent 

 occasion to note the intensity of the so-called " rain-band," an 

 absorption-band of terrestrial origin, due probably to the dust 

 and water-vapour present in the atmosphere, and of just less 

 refrangibility than the less refrangible of the D lines, and have 

 at present two continuous records of observations taken, in the 

 main, five times a day, running back a year and a half or so. 

 I have also a very thorough list of the auroral displays which 

 have occurred for the same period in this vicinity. Granting 

 that the aurora is an electric discharge in high regions of the 



atmosphere, or, more accurately, where its density is inappre- 

 ciable compared with that at the earth's surface, and knowing 

 that according to these recent experiments an electric discharge 

 is capable of precipitating the dust-particles in the atmosphere, 

 it should follow that at times of auroral display, or immediately 

 following, the intensity of this rain-band should be at a mini- 

 mum. Searching the records to ascertain if any such corre- 

 spondence could be noticed, it is quite astonishing to find how 

 distinct and well marked this variation in the intensity of the 

 rain-band at times of auroral occurrence is. The atmosphere is 

 full of fine dust-particles, and our very general, though not yet 

 decisively proven, belief is that the aurora is somewhat of a 

 glow-like discharge from electrified air strata, in whose vicinity 

 the density of the dielectric is inconsiderable. The direct infer- 

 ence is that at such times the fine dust and vapour particles are 

 deposited, made to settle, or, uniting together, form an agglo- 

 meration, and become perhaps cloud-nuclei. Perhaps other 

 evidence on this matter can be elicited. The records at hand 

 show very plainly just such an agreement as was anticipated. 

 Alexander McAdie 

 26, Garden Street, Cambridge, Mass., U.S.A., 

 June 5 



Some Botanical Queries 



There is a plant here with a very large bulb, Sci/la mati- 

 tima (?), whose flower I have not seen. I grew two of them in 

 pots last year, but they failed. This plant is set by the peasants 

 near the fig-trees with the idea that these latter will produce 

 better fruit. Is this a mere superstition? or can the Scilla be 

 connected in any way with caprification ? 



Is Lilium biilinfentm known to be polygamous ? The greater 

 part of the specimens I have found in the mountains near here 

 are staminate, but in some there is a very minute though per- 

 fectly formed pistil. Miiller, my only book of reference, says 

 nothing on this point. 



Is Trifolium rcpens among the list of cleistogamous plants ? I 

 am watching a specimen which seems to produce abundant fruit, 

 but no ordinary flowers. LtGUs 



Nice, France, June 20 



Primaeval Man and Working-Men Students 

 Under the above heading you published a letter from me in 

 Nature, August 2, 1883, p. 320, giving the names of four 

 thoughtful artisans, who, after studying the Pitt-Rivers collec- 

 tion of antiquities, and reading my notes in Nature, had made 

 finds of Palaeolithic implements in Essex. Ten months have 

 passed since that letter was published, and a fifth student, Mr. 

 W. Swain, has now joined the original party of four. On 

 Sunday, June 15, these admirable workers called upon me with 

 their recent discoveries. They consisted of fifteen Palaeolithic 

 implements found in the drift gravels of Leyton, Wanstead, and 

 Plaistow, with the usual complement of flakes. Some of the 

 implements were of the older abraded class, others were as keen 

 as knives, and from my "Palaeolithic Floor, " traces of which, 

 as I have pointed out, may be seen in Essex. Three nonde- 

 script tools were also lighted on, and four hammer-stones of 

 quartzite with abraded ends, one from Nazing ; five Neolithic 

 instruments from Jordan's Wood, and a large collection of 

 flakes. 



The excursions for these tools and flakes have necessarily all 

 been made on Sundays. The finders of the stones are not mere 

 collectors, but men who have mastered the meaning of their 

 subject. W. G. S. 



FORESTRY 

 ""PHE approaching International Forestry Exhibition 

 *■ at Edinburgh, which is to open on July 1 next, and 

 which promises to be a very successful affair so far as the 

 variety of the exhibits and the general arrangements of 

 the Exhibition are concerned, will, it is hoped, prove some- 

 thing more than a mere show during the months it is open 

 to the public. Though the objects exhibited will, in all 

 probability, be a source of considerable attraction and 

 instruction, inasmuch as the arrangement and scope 

 of the several classes seem to have been carefully con- 

 sidered, it is much to be hoped that the Exhibition will be 



