May, 1906.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



433 



declined to commit themselves to such a view. The fomiei 

 stated that he had asked for years how laiid-ice could get 

 to linj^land from Scandinavia over the wide and de('|) 

 channel which contours the latter country, and the b(■^l 

 rcjily he got was that there was a sort of " clearing-house " 

 at tiie Dogger Bank, or that the channel was post-glacial. 

 He had asked how, if distributed by land-ice, .Shap bouMers 

 crossed the ice coming from the Cheviots anil Scotland, 

 and Arenig boulders crossed those from Criffel and the 

 Lake District, and the only answers ignored the physical 

 properties of ice. 



Clay with Flints. 



Years ago, the now veteran geologist, Mr. Willi.un 

 Whilaker, I-M^.S., when engaged on geological survey 

 work in Berkshire, was at a loss to understand the depi;sii 

 of red clayey material which was constantly met with in 

 chalk districts, and which almost invariably contained a 

 large number of unworn chalk flints. In 1864 he ;: ■ 1- 

 pounded a theory, and held that this clay-with-fiints, as he 

 then called it, was a residue from the slow solution of the 

 chalk, although he admitted that it included some mat rial 

 derived from the eocene. Mr. A. J. Jukes-Browne, F.G.S., 

 in conjunction with Mr. William Hill, has now made a 

 careful examination of chalk from various zones, in order 

 to establish whether or no it were possible for the deposit 

 to have been obtained wholly from the chalk, a view wliich 

 appears now to be very largely accepted, and as, indeed, 

 Charles Darwin appears to have thought. In the result, 

 the e.xperiments which have been made show that ko 

 cubic feet of the Micraster-corangiiinum-cha\k will produce 

 only 1.2 cubic feet of clay, and the solution of the 31ar- 

 supites- and Micrasfer-coranriuinum-/.oncii to the extent of 

 200 feet over any part of the area would only yield cUiy 

 enough to make a layer 2 feet deep. Lastly, it is shown 

 that the quantity of flints in the upper chalk is so much 

 greater than the quantity of clay, that the natural residue 

 could not form a clay-wlth-flints. Thus, solution of 100 

 feet of ]\Iicrastcr-coranriuiHum-cha\k would yield a bed of 

 flints about 7 feet thick, and only enough clay to fill up the 

 interstices between the nodules. The experiments practi- 

 cally show that it is impossible to suppose that the clay- 

 with-flints owes its origin to the small amount of clay con- 

 tained even in impure chalk. There is a difficulty in think- 

 ing, on the other hand, that the pipes in chalk, which are 

 filled by this clay, have been filled simply by the falling of 

 tertiary material into holes of pre-eocene formation. That 

 such holes are still extending is an established fact, and, 

 somehow, they become filled by the clay as they e.xtend. I 

 suggest that they become filled by a process akin to 

 infiltration, which leaves the angular flints practically in 

 the same position which they occupied when surrounded 

 by chalk. 



ORNITHOLOGICAL. 



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



A Ctirious Hybrid. 



The interesting collection of hybrids at the Natural History 

 Museum has just been enriched by a life-sized sketch in 

 colours of a very remarkable hybrid bred at Didlington Hall, 

 Norfolk. This sketch, the work of the Hon. Florence Amherst, 

 depicts a male bird, the offspring of a curious blending of 

 breeds, inasnuich as its male parent was a cross between the 

 long.tailed Japanese fowl and a Campine hen, while its female 

 parent was a common hen pheasant. The general appearance 

 of this extraordinary bird recalls that of the common hen ; 

 there are no traces of spurs, and only an indistinct comb, 

 while the tail is short and square. Round the eye is a large 

 vermilion area of bare skin, derived from the pheasant, and 

 similar evidences of pheasant blood appear in the dark blue 

 neck and bright chestnut underparts. Thus this bird exhibits 

 the female characters of its male parent and the male 

 characters of its female parent. 



Mediterranean Shearwater in Sussex. 



At the l.ist meeting of the British Ornithologists Club an 

 example of the Mediterranean shearwater (Piiffmiis kiclili) was 



exhibited, which had been picked up dead on Fevensey beach 

 in February last. This makes the first occurrence of this 

 species in Great Britain. 



King Eider in Orkney. 



Mr. Fred Smalley, in the '• /Zoologist " for March, records 

 the fact that an adult female king eider iSomatcria spcctalilis) 

 was killed at Gra:insay, in February, by Mr. S. Sutherland, of 

 that place. 



Pacific Eider in Orkney. 



In the Fuid, April 7, Mr. H. W. Robinson records the 

 occurrence of " another so-called Pacific eider (Somatcria 

 v-nii;rum) in Orkney, making the third this winter," and 

 remarks that " all these three drakes with the V-mark on the 

 throat are probably common eiders." The fact that this 

 peculiar mark is by no means rare in the common eider is one 

 of considerable interest, and until recently was never sus- 

 pected. But the Pacific eider is generally regarded as further 

 differing from the common eider in that the feathers of the 

 lores in the latter extend so far forward on to the beak that 

 the distance between its furthest point and the extremity of 

 the naked angle on the side of the forehead is greater than the 

 distance from the same point and the tip of the beak, while 

 in the Pacific eider the distance from this point to the bare 

 forehead angle is less than that between this point and the tip 

 of the beak. 



Arriva.1 of Summer Birds. 



The arrival of the following species has already been 

 recorded : — 



House martin — Tenby, March ig (FieM, March 31). 



Sand martin — Wickham, Hants, March 23 ; Hythe, Kent, 

 March 22. 



Willow wren — Eastbourne, March 21 ; Flax Bourton, 

 Somerset, March 23. 



Chiff-chaff — Mitcham, March 17; Bedford, March iS ; 

 Salisbury, March 22 ; Chichester, March 24. 



Wheatear — Richmond Park, March 6; Marazion, Corn- 

 wall, March 11 ; Weston-Super-Mare. March 14. 



Tree pipit — Ashby Pastures. Leicestershire, March 30. 



Redstart — Eastbourne, April 2. 



Turtle dove — Aldringham, Suffolk, April 2. 



PHYSICAL. 



By Alfred W. Porter, B.Sc. 



On the Effect of High Temperature on 

 Radioactivity. 



ExPEKiMFNTS made by Curie and Daune (Comptes Rendus, 

 1904) indicated that the rate of decay of radium C can be 

 altered by subjecting it to temperatures above 630^ C. 



H. L. Bronsoumore recently made experiments from which 

 became to the opposite conclusion. 



The question is a very interesting and important one, for one 

 of the main characteristics of the emanation itself is its indiffer- 

 ence to the circumstances in which it is placed ; hot or cold 

 its rate of decay seems to be absolutely unchanged ; and 

 indeed this is one of the links in the chain of evidence by 

 which it was concluded by Rutherford that the change that 

 proceeds is not of an ordniary chemical type — for the tem- 

 perature has a great influence on every chemical reaction — 

 but is ultra-atomic in nature. 



In order to obtain further evidence Mr. Walter Makower 

 (Harling I-'ellow of the University of Manchester) has recently 

 made a scries of observations on the influence of tempera- 

 ture upon the rate of decay of the Beta and Gamma activity 

 of an equilibrium mixture of radium emanation with its pro- 

 ducts radium A, B, and C. The emanation was enclosed in 

 a quartz tube so that none of the products could escape ; 

 while the walls of this tube were so thick that the .\lph.-i 

 streams were also stopped ; hence any ionisation produced 

 in the air outside must have been due to the Beta particles 

 and Gamma rays. The tube was allowed to ionise the air in 

 a testmg cylinder of the usual type, and thus the activity 

 was measured. If sufficient time were given before the tests 

 for the contents of the tube to come into radioactive equili- 



