276 



KNOWLEDGE & SCIENTIFIC NEWS. 



[November, 1905. 



violet rays from the lamp have also a marked effect upon 

 oxygen according to the results of further experiments made 

 by Drs. Fischer and Braehmer. When pure oxyRen is con- 

 ducted through the lamp with precautions to keep the tem- 

 perature low, a considerable proportion of ozone is formed, 

 the yield increasing with the strength of the light up to a 

 certain point and then diminishing. If the temperature is too 

 high no ozone is produced, since that first formed is recon- 

 verted into oxygen. It is pointed out that these experiments 

 support Warburg's view that the formation of ozone notice- 

 able in silent electric discharges is due to the emission of 

 ultra-violet light. 



GEOLOGICAL. 



By Edw.\rd a. Martin, F.G.S. 



The Age of the Earth. 



Professor Sollas is always interesting', whether he is 

 reading a paper, and laying himself open to the criticism of 

 others, or whether he is criticising with sledge-hammer blows 

 a paper given by one of his geological colleagues. But he 

 takes criticism in good part, and it is well that he does, for he 

 has given every- opportunity for it in his " Age of the Karth " 

 (Fisher Unwin). He does not exactly say how long the 

 stratified deposits of the earth have taken in forming, but 

 leaving aside the possibility of radium and other radio-active 

 bodies acting in such a way as to upset all preconceived ideas 

 on the subject, he gives us the total of twenty-six millions of 

 years as the time which would have been necessary to deposit 

 all our sedimentary formations, at the assumed average rate of 

 accumulation of one foot in a centur)-. In asking, how far 

 does this period satisfy the demands of biology, although he is 

 aware that eminent biologists are not wanting who share his 

 opinion, he answers for himself. Amply. He might also have 

 added that there are many who c.innot share the opinion. 



Thickness of the Earth's Sedimentary 

 Formations. 



Incidentally, it is interesting to note the sum total of the 

 maximum thicknesses of the sedimentary deposits, so far as 

 Professor Sollas has been able to discover them. He gives a 

 total of 265,000 feet, or about fifty miles, at the base of which 

 are the great American pre-Cambrian formations, Htironian, 

 18,000 feet ; Penokee, 14,000 feet ; Keweenawan, 50,000 feet ; 

 although there seems to be some doubt as to the thickness of 

 the last-mentioned. It will be necessary for our text-book 

 writers in future to have a care not to repeat the oft-quoted 

 thickness of about a dozen miles of sedimentary rocks. 



The Sun ais a Non-Luminous Star. 



Sollas quotes Kelvin's argument that the life of the sun as a 

 luminous star is even more briefly limited than that of our 

 oceans. This means that if the age of the sedimentary rocks 

 is as already given, our oceans may have been formed fifty- 

 five millions of years ago, and that after a short existence 

 almost as boiling water, they grew colder and colder, till they 

 became covered with thick ice. So the earth may have re- 

 mained, frozen and dark, until in obedience to the growing 

 splendour of the sun, the long night of the earth became 

 bani.shcd, and the commencement of rtmning wafers was the 

 beginning of the formation of the sedimentary rocks. Just one 

 suggestion here. Is it altogether inconceivable that life may 

 have existed in the heated waters of the earth in the days 

 of the non-luminous sun ? 



The Radium "Apparition." 



Professor Sollas speaks pictMres(|Mely of a now cause of dis- 

 tarbance, which looms up before us, " vague and gigantic, 

 threatening to destroy all faith in hitherto ascertained results, 

 and to shatter the fabric of reasf)ning raised upon them." 

 This appantion is radium. If the earth posses.ses radium 

 throughout its mass to the extent of one five-millionth of 

 a gram per cubic me'.re, it has been asserted that the whole 

 of the heat lost by radiation into outer space would be com- 

 pensated for, and the temperature gradient would be un- 

 changed for a very- long period. So the geologist breathes 

 freely again, and blesses the apparition. 



Fossil Trees in Victoria Park, Glasgo>v. 



Glasgow is fortunate in possessing, in its \'ictoria Park, the 

 remains of an old carboniferous iMndsurface, which when laid 

 bare showed a number of petrified broken trunks and roots of 



Fussil Tree Trunk i5iglllarla), Qlasgo' 



Sigillaria. These have wisely been protected, and by the 

 erection of a commodious shed over them, have been pre- 

 served from the effects of the weather. We reproduce some 

 photographs of them. We know of no object-lesson so hkely to 



Fossil Tree Trunk (Sigillaria), Glasgow. 



arouse interest in the study of geology as that presented by these 

 easily-accessible specimens of a by-gone age. We plead for a 

 better use of such specimens, and for a more general adoption 

 of the study of geology in our Polytechnics. 



OR.NITHOLOGICAL. 



By W. P. PvcKAiT, A.L.S., I".Z.S., M.I5.0.U., &c. 

 Bee-ea-ters in Yorkshire. 



The Zoolot;isl for CJctober reports the occurrence of three 

 Bee-eaters at Bentham, ^'orkshire, during the middle of Sep- 

 tember. They had halted by the way in a garden, where they 

 discovered a promising supply of food in the occup.ints of a 

 number of beehives. On one of th(- nunil)cr, an adult male, 

 being shot, however, the rest appi-ar to have moved off to 

 safer quarters. 



Hoopoe in Sussex. 



Mr. J. S. Snelgrovc writes to the I'uUI, October 7, to say 

 that he saw a Hoopoe on September zf> at Kotherfield, Sussex. 

 The bird was sitting in a cart rut, but rose (luickly and flew 

 out of sight behind some trees. Doubtless we shall soon hear 

 that it has been shot. 



