June, 1905.^ 



KNOWLEDGE & SCIENTIFIC NEWS. 



133 



works farther up. At Kenley, where building has been going 

 on for some time, the gravel has been excavated and sifted. In 

 a heap of gravel which I examined, in addition to a great 

 number of sub-angular flints, there was a fair proportion of 

 rounded stones and pebbles, of Oldhavcn pebble-bed origin. 

 Many of the tlints had become encrusted with a covering of 

 lime, after the manner of the action of so-called petrifying 

 springs. Lumps of conglomerate were also found, and 

 occasional pieces of red sandstone. The limestone encrusta- 

 tion of some of the flints clearly showed the present origin of 

 the feeding springs from the chalk, whilst the presence of the 

 sandstones takes one back to times when the river had a por- 

 tion of its flow over the Lower Greensand farther south, and 

 possibly over some of the sandstone beds of the Weald. 

 » » » 



Pre-Gla.cia.1 Valleys of the Northximber- 

 latnd and Durham Coalfield. 



By a detailed examination of about 600 different borings in the 

 areaspecified. Dr. D. Woolacott, F.G.S., has reconstructed with 

 considerable pains some of the valleys which existed prior to the 

 Ice Period, many of which have been completely hidden since 

 by thick wrappings of boulder-clay. Although the subsequent 

 existing drainage systems of boulder-clay areas are in most 

 cases much the same as those on which they were super- 

 imposed, there are notable cases in which the subsequent 

 drainage has been completely different to that previously 

 obtaining. The greatest thickness of superficial deposits found 

 was that at Newton Hall, in the Wash valley, when 233 feet 

 of these lay above the old rock surface. A number of the 

 borings show the rock-surface at a considerable depth below 

 sea-level, such at Burdon Main, in the Tyne valley, where 

 the rock was not reached except at a depth of 141 feet, this 

 affording good evidence of considerable subsidence, as 

 compared with pre-glacial time?. 



* * * 



The Great Peak Fault. 



In the course of a paper read before the Geological Society 

 by Mr. R. H. Rustall. B.A.. on the Blea-Wyke Beds and 

 the " Dogger " in N.E. Yorkshire, the subject of the age of 

 this well-known fault was touched upon. The author leaned 

 to the view that it was partly of pre-Oolitic date. There is 

 every reason to think, as suggested by Mr. Hudleston many 

 years ago, that the fault was a distinct line of weakness, and 

 that probably movement had taken place more than once in 

 the history of the district. Disturbances in the earth's crust 

 were apt to follow old lines. 



* * ♦ 



Earthquake in England. 



A reminder on a small scale of the earthquake convulsions 

 which have taken place recently in India was experienced in 

 the Midlands on the early morning of Easter Sunday. It is 

 not improbable that the shock had a connection with the 

 Indian catastrophe. The crust of the earth will for some time 

 be occupied in settling down, so to speak, into greater per- 

 manency than it was left after the great underground earth- 

 slides which gave rise to the Lahore shocks. In fact, anyone 

 great quake may generally be regarded as the forerunner of 

 other minor ones, and the shocks so caused may travel to 

 regions where earthquakes are infrequent. 



-^^^^^^ 



ORNITHOLOGICAL. 



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



Greenland Fa.lcon in Co. Donegal. 



In the Irish Naturalist for May, Mr. Robert Patterson records 

 the occurrence of a Greenland Falcon at Horn Head, Dun- 

 fanghy, on March 21. The bird was taken in a trap, and 

 proved to be a female. The total length of this bird from the 

 tip of the beak to the tip of the tail was i ft. 1 1 ins. ; the expanse 

 of the wing 4 ft. 3 ins. The weight is not recorded. 



Corn Crake in Winter. 



Though it is now generally believed that th<! Corn Crake not 

 seldom remains throughout the winter in Ireland, authenticated 

 instances of this stay are valuable. Mr. Robert Patterson 

 records in the Irish Naturalist for May the fact that one of 

 these birds was shot near Lurgan in January last. In England 

 such cases are very rare. 



Bittern in Co. Wexford. 



One of these unfortunate liirds was shot in November, 1904, 

 at Curracloe, near Wexford. Accordingto Mr. J. H.Johnson, 

 who records this occurrence, a Mr. O'Neill heard the booming 

 near his house. This statement requires some qualification, as 

 the Bittern is generally believed to utter this note only during 

 the breeding season. 



Snowy Owl in the ShetlaLnds. 



One of these birds was killed in November last, .according to 

 the Ayinals of Scottish Natural History for April (which reached 

 us too late for comment last month) at Ballinata. No parti- 

 culars are given as to sex or measurements. News has just 

 come to hand of another Snowy Owl killed in Norfolk during 

 April last. Further particulars thereof we hope to give next 

 month. 



» * * 



Albino Redshank in the Outer Hebrides. 



A so-called albino Redshank was killed in October last in 

 the Outer Hebrides, according to the Annals of Scottish Natural 

 History for April. This bird, however, should rather have 

 been described as isabelline and white, inasmuch as buff and 

 cinnamon appeared conspicuouslv in the plumage intermixed 

 with white. In true albinos, all pigment is wanting ; hence the 

 pink iris, which is hall-mark of the albino. 



Arrival of Summer Birds. 



From The Field for .^pril 22 we gather the following list :- 

 Garden Warbler — St. Neots April 13 



Nightingale 



Landrail 



Eastbourne 



Tonliridge 



Shoreham 



Shere 



Hockley ... 



Barnstaple 



PHYSICAL. 



By Alfred W. Porter, B.Sc. 



All who had the privilege of listening to Professor Nichols 

 (of Columbia L'niversity, New York) at the Royal Institution, 

 on the 12th May, were delighted with the apparent ease with 

 which a difficult experiment was shown. The subject of the 

 lecture was " The Pressure due to Radiation." It had been 

 predicted by Maxwell that if his electro-magnetic theory were 

 true, light falling on a body should repel it, and he calculated 

 the force of the repulsion which would correspond to a par- 

 ticular amount of light; but this was exceedingly small. 

 Crookes at first thought he had obtained experimental evi- 

 dence of this pressure when he discovered that light vanes, 

 mounted in a partial vacuum so as to be capable of easy rota- 

 tion, were set in motion when one side of each face was 

 blackened and light fell on the blackened face. This action, 

 however, was afterwards traced to the effect of heat and not 

 to light, and depends upon the presence of residual air in the 

 exhausted vessel. 



This air effect, when at a maximum, is thousands of times 

 as great as the effect which would exist if no air were present ; 

 and it is its presence which creates the chief difficulty in 

 measuring the pressure due to radiation itself. 



