28o 



HA RD WICKE'S SCIENCE- G OS SIP. 



Channel Islands. — The locally-called " wild 

 rhubarb " (Gunnera scabra) was brought from Mexico 

 in 1851 by Mr. Henry Dobree, of St. George, Guern- 

 sey, and was planted at the Vallon by Mr. Carey in 

 1853, and has flourished there ever since. The 

 plants noticed in the glen leading down to Moulin 

 Huet Bay are seedlings from the original plant in the 

 Vallon Garden. — 21 1. Daubre, Guernsey. 



Erica ciliaris. — Mr. Porter, in his graphic 

 description of that splendid plant, the Erica ciliaris, 

 has stated that it is not entirely confined to Cardew ; 

 in that he is correct, for I can inform enterprising 

 botanists that they have no need either to trouble the 

 owner of Cardew or his pheasants, as they can find 

 the plant for themselves flourishing plentifully on 

 moory ground in more than one spot both north and 

 south of Truro, not far from that city ; at least it was 

 so in the years 1873 and 1874, when I gathered it. 

 I also found growing along with it, in one locality to 

 the south, that very pretty hybrid variety, Tetralix 

 ciliaris. Although Mr. Porter has by no means over- 

 rated the beauty of ciliaris, yet I think it hardly yields 

 in elegance to its congener, E. vagans, growing, as 

 the latter does, in such masses that it is worth taking 

 a journey to its habitat (or one of its habitats, for I 

 have only seen it there), near the Lizard, if for 

 nothing else than to see it in full bloom in the month 

 of July.— J. W. D. Keogh. 



GEOLOGY, &c. 



The Pal^ontological Society. — We are sorry 

 to see that this, one of the oldest and most useful of 

 scientific associations, is in peril of its life for lack 

 of funds. For more than thirty years its annual 

 volumes, describing British fossils, have increased 

 in value. The yearly subscription is one guinea, 

 for which each subscriber receives the large quarto 

 annual volume and illustrations. The falling' off in 

 the receipts has come from the old subscribers dying 

 off, and new ones not being forthcoming to take their 

 places, doubtless because the latter do not understand 

 the advantages. 



Glass 100 Feet in Thickness.— Among the 

 numerous objects of interest discovered by the Geo- 

 logical Survey of America, remains of extinct animals 

 and natural phenomena, not the least interesting, 

 perhaps, is an obsidian cliff. This cliff is about 

 half a mile long, by from 150 to 250 feet high, 

 the material of which is said to be as good glass 

 as any artificially manufactured. Its colours and 

 structure, not only make it highly interesting, but 

 furnish to the scientific investigator phenomena of 

 importance. The cliff presents a partial section of 

 a surface flow of obsidian, which poured down an 



ancient slope from the plateau lying east. It is 

 impossible to determine what the original thickness 

 of this flow may have been, but the dense glass 

 which now forms its lower portion is from 75 to 100 

 feet thick, while the porous and pumiceous upper 

 portion has suffered from ages of erosion and glacial 

 action ; a remarkable feature of the cliff is the de- 

 velopment of prismatic columns. These are of 

 shining black obsidian, rising from the talus slope, 

 and are from 50 to 60 feet in height, with diameters 

 varying from 2 to 4 feet. The colour of the material 

 of the cliff is, for the most part, jet-black, but much 

 of it is mottled, and streaked with bright brownish- 

 red and various shades of brown and olive-green. 

 In some places the material shows a fine satin lustre, 

 while in others a deep golden sheen is noticeable, 

 which, under the lens, resolves itself into thin beams 

 of red and yellow light. — Dipton Burn. 



Important Geological Discoveries in Aus- 

 tralia. — A very important geological discovery has 

 recently been communicated by Mr. C. S. Wilkinson, 

 the Chief Geological Surveyor for New South Wales. 

 It is connected with the dock excavations going on 

 in Cockatoo Island, where the Hawkesbury sand- 

 stones are being quarried. Not only have fossil 

 plants been found, but a small fossil shell, a Planorbis. 

 The Planorbis is a freshwater shell ; and there is a 

 controversy going on concerning the origin of the 

 Hawkesbury sandstone, which this little fossil shell 

 may be required to give evidence upon. Encouraged 

 by the above "finds," Mr. Wilkinson sent the collector 

 to make further search, and he was rewarded by 

 discovering the remains of the first fossil (Labyrintho- 

 dont) yet met with in Australia. These remains 

 have been identified as those of a Mastodontosaurus, 

 which, in Europe, is confined to the Lias formation. 



Geological Pamphlets. — We have received 

 Mr. F. C. J. Spurrell's elaborate "Sketch of the 

 History of the Rivers and Denudation of West Kent " 

 (illustrated) ; Dr. H. W. Crosskey's " Glacial Geology 

 of the District around Loch Leven, Argyllshire," and 

 the last Report of the Gold-fields of Victoria up to 

 June 30, 1886. 



Harris's "British Petrography." — rart ix. 

 of this beautifully got up and most useful work is 

 published with coloured plates, showing the micro- 

 scopical structures of Plagioclase, Augite-Olivine 

 rock, and Hornblendic Gabbro. 



SCIENCE DIRECTORY. 



Kendal Natural History Society. — Chairman, Rev. 

 George Crewdson, M.A. Hon. secretaries : Joseph 

 Severs, and George Cartnel, Kendal. 



