66 



KNOWLEDGE & SCIENTIFIC NEWS. 



[March, 1907. 



GEOLOGICAL. 



By Edward A. Martin, F.G.S. 



The Geological Society of London. 



I'm prosperous ami flourishing condition of the Geological 

 ol London is n matter of considerable public interest. 

 i 1 the reporl ol the Council for 1906 we find thai the 

 yn u closed with a total Fellowship oi 1,252. Hie Society 

 will celebrate the centenary ol its founding in September 

 next. This will be an interesting function, and ii is hoped 

 thai man) delegates from kindred institutions al home and 

 ibroad will attend. Mr. II. B. Woodward's Historj of the 

 s ,cicty has now been completed, and the author is engaged 

 in passing it through the press. The Wollaston Medal, the 

 blue-ribbon of the geological world, has been awarded to 



sor \V. |. Sollas.F.R.S., the Murchison Medal has 

 been awarded to Mr. Alfred Harker, F.R.S., and the Lyell 

 Medal to Dr. I. !■'. Whiteaves, .1 sum of money accompanj 

 ing the awards in the lasl two cases. No awards arc made 

 this year from the Barlow-Jameson Fund, the Prestwich 

 Trust Fund, and the Daniel-Pigeon Fund. The Council 

 have exercised their powers very laudably in the allotment 



various funds, and it is believed there is greater deter- 

 mination now to find oul workers in the provinces who have 

 merited well of the science, and whose efforts sometimes 

 languish for want of encouragement. It is hoped that the 

 claims of the amateur geologist will receive full considera- 

 tion, both in the mailer of awards, and in the recommenda- 

 tions of the Council for seats on its own body. 



The Victoria Falls. 



The geology of the Zambesi Basin around the Batoka 

 Gorge (Rhodesia) was the subject of an interesting paper 

 read by Mr. G. W. Lamplugh, F.R.S., on January 23, at 

 Burlington House. The author described in a most interest- 

 ing and effective manner the portion of the river Zambesi 

 as' it Hows through the great gorge, which forms the exit 

 of the river after plunging down the Victoria Falls. Above 

 the Falls the river has many channels, more or less shallow, 

 and has here apparently reached the last stage of old age. 

 The flow above is of a tranquil nature, and in times of 

 drought great islands appear in the stream. Were it not for 

 the fact that, just when it was approaching that stage when 

 further excavation was almost impossible, and its waters 

 were likely to spread over a wide area of basin, it found a 

 weakness in its bed in the shape of transverse-fractured joint 

 or series of joints, its rejuvenescence would not have been 

 accomplished. Finding, however, this fracture filled up with 

 easily-excavated material, it proceeded to denude it, with 

 the result that after the lapse of long periods of time, the 

 whole river now falls into the chasm. The exit of the river 

 is not the full width of the chasm ; in fact, the exit is com- 

 paratively narrow, and as this was presumably eroded 

 where the process was easily done, it adds additional pro- 

 bability to the theory thai the chasm of the fall was what 

 may be called a rubble-filled fracture, easily disintegrated 

 along its whole width. The width of the issuing stream as 

 compared with the width of the falls is a phenomenon which 

 may be satisfactorily thus accounted for. Mr. Lamplugh's 

 vivid description of the geology of the neighbourhood was 

 admirable in every way, and it was well illustrated by a 

 well-chosen set of slides. But the subject is a great one, 

 and he was careful to show in what direction future cx- 

 plori rs may prosecute their researches. 



Earthquake Origins. 



It is unsafe to deny that volcanos and earthquakes have 

 at times a real connection, although it may be that -some- 

 times the one or the other may be alone noticeable. Earth- 

 quakes may and do undoubtedly arise from explosions in 

 volcanos, but many arise from other causes. The sudden 

 formation of a fissure far underground, or the extension of 

 a fault already in existence, may result in an earthquake, or 

 even the collapse of the roofs of caves in a limestone district 

 mav give rise to one. The results of numerous investiga- 

 tions have showai that some of the most appalling catas- 

 trophes have their origin at a very slight depth, as compared 

 with the earth'- radius. Even the Charleston earthquake of 

 1886 had its origin bill about 12 miles below the surface, 



and probabl) the seal of origin in no case exceeds 20 miles. 

 The outermost crust only seems to contain the yielding 

 matei ial ; beyond it all is too compact to produce movement. 

 The renl in the rocks which is thought to have caused the 

 Charleston earthquake mad'' its effects felt from Boston to 

 Cuba, and from Eastern Iowa to the Bermudas. The vibra- 

 tions of a shock may be compared to the vibrations caused 

 in air during the production of sound, such as when a sudden 

 shoul is made. Each particle of the earth vibrates rapidly, 

 the swing of each particle probably, as a rule, not exceeding 



a tenth of an inch, but the movement is there, and the shock 



ol this light movement of millions of particles, and their 

 sudden arrestmenl and retrograde movement, are sufficient 

 to cause the appalling results of a greal quake. Frequently 

 after an earthquake land is found to have been raised, as, 

 for instance, in iX_>.?, when the coast of Chile was suddenly 

 raised three or four feet. Al other limes there is a sudden 

 depression, as in 1 S 1 2 , when a region of 75 miles by 30 

 miles, resulted in the production of swamps and shallow- 

 lakes in New Madrid, Mo. These phenomena must be rc- 

 garded not as the effects of an earthquake, but rather as the 

 visible effects of the disturbance lo which the' earthquake is 

 due. Xoi necessarily, linn, an earthquake is caused by a 

 connection with an outburst of volcanic energy, but as any 



shock to tin- crusl must result in a quake- of some sort, sec 

 volcanic explosions may give rise to local earthquakes, 

 although these mav not be felt many miles away from the 

 volcano. On the other hand, the deeper that volcanic ex- 

 plosion may occur, to the greater distance will the shocks 

 be felt, and we cannot safely say from negative evidence 

 alone, that volcanic action is not at work beneath our feet, 

 resulting in quakings of the earth. 



ORNITHOLOGICAL. 



By W. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c. 



Ailsa Craig. 



Considerable alarm has been created among bird lovers 

 by the news that Ailsa Craig has been let by its owner, for 

 a term of thirty years, for quarrying purposes on an exten- 

 sive- scale. It is felt that this may have disastrous results 

 in the bird colonies established there, partly on account of 

 the blasting operations necessary for the dislodgment of 

 the granite, and partly by the raids which will probably be 

 made on the breeding birds by workmen and others. That 

 such fears are not unfounded may be gathered from the 

 fact that at the last meeting of the British Ornithologists' 

 Club the matter was seriously discussed ; and, on the pro- 

 pi esit ion of the lion. Waller Rothschild, it was at last 

 decided to appoint a deputation of the Club to approach the 

 Marquis of Ailsa, with a view to secure his interest in the 

 matter, in the hope thai he may be induced to take all 

 possible precautions to secure the birds from molestation. 



The Eggs of the Solitary Sandpiper. 



At the meeting of the British Ornithologists' Club held 

 on January 16, Major 1". W. Proctor exhibited three sets of 

 eggs of tin- Solitary Sandpiper (Totanus soli far ins) procured 

 in Northern Alberta, N.-W. Canada, in June, 1903. These 

 eggs excited considerable interest, inasmuch as they an- the 

 first that have ever been brought to Europe. But, in addi- 

 tion to their rarity, these eggs were remarkable on account 

 of the light which they shed on the peculiar nesting habits 

 of this bird. Thus, the first clutch contained live eggs 

 taken from an old nest of the American Robin (Ttirdus 

 migratorius). The second was incomplete, (wo e-i^gs only 

 being found, and these in a nest of Brewer's Blackbird 

 (Scolecophagus cyanoeephalus) placed in a tamarie tree five 

 feet from the ground. The third was represented by three 

 eggs also taken from a nest of the American Robin about 

 15 feet from the ground. The normal clutch appears to con- 

 tain four eggs, which are laid in the deserted nests of other 

 birds, and at some distance from the ground. 



Destruction of the Kite in Wales. 



We regret to have to draw the attention of our readers to 

 the fact that a Common Kite has recently been killed near 

 Brecon. In a letter to the Field (February q), Mr. Cam- 



