July 9, 1903] 



NATURE 



233 



value than those found in the coast shell-heaps, and skele- 

 tons are frequently found in the former and but rarely in the 

 latter. It is probable that at an early time a migration 

 tooic place from the interior to the coast and Vancouver 

 Island. This migration carried the art of stone-chipping, 

 pipes and decorative art to the coast. The culture of the 

 ancient people who discarded the shells forming these heaps 

 was in all essential particulars similar to that of the tribes 

 at present inhabiting the same area, but it was under 

 . much stronger influence from the interior than is found 

 ut the present time. 



Arch.TiOlogical excavations have been made by Lieut. 

 r.. Desplagnes in the tumuli qf Killi, in the region of 

 Goundam, in the neighbourhood of Timbuktu (c/. 

 VAnihro\,o\ogic, tome xiv. p. 151). The mounds appear 

 to have been the tombs of chiefs, along with whom were 

 buried women and captives, and large quantities of offer- 

 ings of various kinds. The originators of these funeral 

 monuments surpassed the existing people of the district in 

 the art of making varnished pottery and in the fabrication 

 of bronze. The presence of marine shells shows that they 

 had relation with maritime peoples, and other objects prove 

 an extensive commerce. There appears to be some evidence 

 that these unknown people were partly related to the 

 Berbers, and that they were overwhelmed by the spread 

 of Islamism in the eleventh century. The author thinks 

 that perhaps certain isolated peoples whom he mentions 

 may be the fugitive remnants of this formerly relatively 

 advanced nation. 



A ME.MOiR on the geology of North Arran, South Bute 

 and the Cumbraes, with parts of Ayrshire and Kintyre, has 

 just been issued by the Geological Survev. It is the work 

 mainly of the late William Gunn, with contributions by 

 Sir A. Geikie, Dr. Peach, and Mr. A. Harker, and is an 

 explanation of Sheet 21 of the one-inch map of Scotland 

 A great variety of subjects is dealt with, as may be gathered 

 from the lengthy table of formations represented, and there 

 IS much to justify the statement referred to by the authors 

 that the geology of Arran is an epitome of that of Scotland' 

 The central granite mass forms the dominant feature 

 rismg to 2866 feet at Goatfell, and it is bordered by the 

 older metamorphic rocks, schists into which, as observed 

 by Hutton more than a century ago, the granite has been 

 mtruded. Rocks probably of Arenig age, black schists 

 cherts and grits, similar to those of Ballantrae, and associ- 

 ated with old lavas and tuffs, have been discovered in the 

 course of the survey. Notable additions have also been 

 made to our knowledge of the volcanic rocks, and especially 

 with respect to a huge volcanic vent, probably of Tertiary 

 age, in which are preserved remnants of Rh^tic, Liassic 

 and Cretaceous formations, hitherto unrecognised in the 

 r.»gion. Full particulars are given of the granite, and of 

 the dykes and sills of felsite and quartz porphyry, pitch- 

 stone, and other Tocks. The Old Red Sandstone and the 

 Carboniferous rocks, the determination of the Triassic age 

 • the newer red sandstones, conglomerates and marls, and 

 • accounts of the Glacial phenomena and economic 

 'logy, furnish many topics of great interest. The memoir 

 nains ten photographic plates, and is issued at the price 



Ihe additions to the Zoological Society's Gardens during 

 •3 past week include a Pinche Monkey {Midas oedipus) 

 Horn Colombia, presented by Mr. E. G. Percy; two Grey- 

 headed Love-birds {Agapornis cana) from Madagascar, pre- 

 nted by Miss Luff; a Whistling Swan {Cygnus colum- 

 nius) from North America, presented by Dr. Cecil French ; 

 NO. 1758, VOL. 68] 



a Mexican Snake {Coluber melanoleucus) from Mexico, pre- 

 sented by Mr. W. G. Kershaw ; two Whistling Swans 

 {Cygnus columbianus), a Mocassin Snake {Tropidonotus 

 fasciatus), a King Snake {Coronella getula), two Mexican 

 Snakes (Coluber melanoleucus), a Seven-banded Snake 

 {Tropidonotus septemvittatus), two Testaceous Snakes 

 {Zatnenis flagelliformis), a Striped Snake {Tropidonotus 

 ordinatus sirtalis), a Long-nosed Snake {Heterodon nasicus) 

 from North America, a Chained Snake {Coluber catenifer), 

 a Couch's Snake {Tropidonotus ordinatus couchi) from 

 California, a Horned Lizard {Phrynosoma cornutum) from 

 Mexico, two Smooth Snakes {Coronella austriaca), an 

 Ocellated Sand Skink {Chalcides ocellatus), European ; a 

 Black-faced Spider Monkey {Ateles ater) from Eastern Peru, 

 a Common Rat Kangaroo {Potorous tridactylus), two Brush 

 Bronze-winged Pigeons {Phaps elegans) from Australia, a 

 Banded Aracari {Pteroglossus torquatus) from Central 

 America, a Rat-tailed Opossum {Didelphys nudicaudata), a 

 Salvin's Amazon {Chrysotis salvini) from South America, 

 two Cutthroat Finches {Amadina fasciata) from West 

 .Africa, deposited ; a Yak {Poephagus grunniens), born in 

 the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Comet 1903 c. — The following elements and ephemeris 

 have been computed by M. G. Fayet, Paris, from observ- 

 ations made on June 22, 24, and 27, and published in 

 Circular No. 60 of the Kiel Centralstelle : — 



Elements. 

 T= 1903 Aug. 28-4715 {M. T. Paris). ■ 



«=I25 56 53 ^ 

 Si =293 38 40 hi903 o. 

 1= 84 6 48 j 

 •ogi' = 9'539534 



Ephemeris izh. (M.T. Paris). 



1903 a 



h. m. s. 



July 5 ... 21 27 33 



„ 9 ... 21 6 46 



,, 13 ... 20 26 15 



„ 17 ... 18 53 22 



,, 21 ... 15 46 14 



& log .1 Brightnes.s 



+ 12 109 ... 96105 ... 4*5 



+ 24 44-8 ... 9-5213 ... 7-6 



+ 3« 57*9 - 94322 .. 12-9 



+ 60 430 .. 94424 ... 14-1 



+ 68 40-8 ... 9-4948 ... 12-9 



On July 13 the comet will, according to the above 

 ephemeris, be about 7m. 20s. following, and sS'-g south of 

 7 Cygni, whilst on July 21 it will be seen in the constel- 

 lation Draco a little more than one-third .the distance from 

 7 Ursae Minoris to tj Draconis on a straight line joining 

 these two stars. 



The above scale of brightness takes for its unit value the 

 brightness at the time of discovery, and on June 25, when 

 the value on this scale was about 1-4, M. Pidoux recorded 

 that the comet was equal in brightness to an eighth magni- 

 tude star. 



Penetrative Solar Radiations. — In a paper com- 

 municated to No. 24 of the Comptes rendus, M. R. 

 Blondlot describes some simple experiments he has per- 

 formed which appear to show that certain rays (which he 

 calls " the n rays ") emitted by the sun are capable of 

 passing through various kinds of wood, metals, &c. He 

 placed a fine glass tube containing a phosphorescent 

 material, e.g. sulphide of calcium, in a darkened room in 

 which there was a window exposed to the sun, but closed 

 by means of an oaken shutter 15mm. thick, and then found 

 that the phosphorescent material, which he had previously 

 exposed for a very short time to feeble sunlight, continued 

 to glow, but if a plate of lead were interposed between the 

 shutter and the tube the phosphorescence became feebler, 

 whilst it again increased when the lead was removed. Then 

 an oaken joist 3cm. thick, a piece of cardboard, and several 

 plates of aluminium were successively interposed, and the 



