August, 1906.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



509 



a mesa, with precipitous sides. The grassy trough in 

 which the mesas occur is a wide canyon-like valley, more 

 than ten miles long, by two to four miles wide, and it is 

 itself surrounded by vertical walls. This valley has been 

 carved out by erosion into curious and bizarre forms. The 

 strata of the plateau, by the dissection of which the mesas 

 have been left high and dry, consist of variegated layers 

 of sandstone, shale, and limestone, " of Pateozoic and 

 Mesozoic ages," and lie as a rule with but a slight dip. 

 The plateau itself is from 4,000 feet to 8,000 feet above tide, 

 and the mesa rises precipitously from the flat plain, which 

 forrn.-^ the canyon-like valley, to a height of 430 feet from the 

 middle of the plain. The name of the Garden of the Gods 

 has been poetically applied to the valley, and undoubtedly 

 it is of immense interest from the archaeological as well a^ 

 from the geological point of view. 



Ne\v Fossil Walrus. 



In the American .Tmi nml »/' Svimrr, fur June, a magazine 

 which was founded by Benjamin Silliman, as far bac,< 

 as 1818, we note a description of a new genus and species 

 of walrus founded on a left mandibular ramus, which wa^ 

 discovered b)' a student of the John Hopkins University, 

 Mr. W. E. Curley, on a beach, at Vorktown, Va., a 

 Terti.jry litlorai deposit. It has been named I'rorosmarus 

 alleni. 



Diplodocus. 



Mr. VV. J. Holland has dt^cribed in "The Osteology of 

 Diplodocus Marshii " the additional material which has 

 been collected since Hatcher's account was first published. 

 He also gives an account of the restoration of Diplodocus 

 recently presented to the British Museum. He includes a 

 detailed description of the atlas, sternal plates, and the 

 bone supposed to be the clavicle. The dorsal, sacral, and 

 caudal vertebr.-e, and the chevrons, are also included in 

 the description. 



Some London Borings. 



The varying dcptlis under Lmidun .it which the chalk has 

 been tapped in deep wells is shown by some recently-made 

 borings, conducted by Messrs. C. Isler and Co 

 At Kentish Town (Prince of Wales Road Baths) there was 

 124 feet of London clay, 46 feet of Woolwich and Oldhavcn 

 beds, and 34J feet of Thanet sands, above the chalk, which 

 was reached at 2055 feet. At the Baltic Exchange, E.G., 

 the chalk was found at 211 feet, there being 112 feet of 

 London clay, 42 feet of Woolwich and Oldhaven beds, and 

 .S7 feet of Thanet sands and basement beds. In the 

 Woolwich beds there is included a thickness of 20 feet of 

 " black rock." This, probably, represents the coaly or 

 lignitic layer which is .sometimes found in the series. The 

 thickness is, however, unusual. At Upper Clapton (Lea 

 Valley Works), the chalk was met at 120 feet, but across 

 the river, at Camberwell (Warner Road), the chalk had 

 sunk to 163 feet, whilst eastward therefrom it rose again 

 to 134 feet at Church .Street, and to 135 feet in the Old 

 Kent Road. This is in accordance with the well-known 

 rise of the chalk at the inner south-eastern corner of Lon- 

 don, whilst at the extreme opposite coiner the chalk, alreadv 

 noted at Kentish Town as at 205^ feet, sinks still furth." 

 at Willcsdcn Junction (.\cton Lane), to 340 feet. .'\t the last 

 mentioned place the chalk was pierced, and attained ;i thick- 

 ness of 580^ feet, the g'ault being bored to the extent of 80' 

 feet, with no intervening upper greensantl. The tot.al 

 depth bored was i,ooo.\ feit, and the well must be considered 

 one of London's deeper wi 11^. 



ORNITHOLOGICAL. 



a pair have just succeeded in hatching out two nestlings, 

 while another pair have made a crude nest of sticks, but so 

 far no eggs have been laid. 



The eggs of the first pair were laid at intervals of three 

 days, the first being laid on May 24, the second on the 

 27th. Incubation lasted five weeks, and did not begin until 

 the second egg was laid. The site selected for a nursery 

 \yas a shelf of rock about half way up the cliff of the sea- 

 lions' pond ; while the second pair have chosen a place much 

 lower down, and in a cave-like recess, thus more nearly 

 resembling the burrow in which these birds usually build. 



The work of incubation was undertaken by both parents, 

 and both share in the work of feeding the young, a tas'c 

 which is performed by inserting the bill within that of the 

 nestling, a method exactly opposite to that practised by the 

 cormorants and some other species. 



Although this is the first time that this bird has bred in 

 these gardens, young have been reared in the Jardi;i 

 d'.Xcclimatation, in Paris. 



Peregrine Falcon Breeding in Yorkshire. 



Mr. T. H. Nelson, in the Fifhl, June 23, records the 

 welcome news that a pair of peregrine falcons have succeeded 

 in rearing a family of three during the present nesting 

 season, thanks to the co-operation of the cliff-climbers of 

 Bempton. It is just a quarter of a century since a pair of 

 this species performed a similar feat. Mr. Nelson expresses 

 a hope, in which all bird lovers will share, that the parent 

 birds will not be molested during the coming shooting 

 season ; since, should they be spared, we may, as he remarks, 

 see this ancient haunt re-tenanted, and thus an added 

 interest will be secured to the magnificent cliff scenery of the 

 Yorkshire coast. 



Roller in Scotland. 



Tlu' " .-\nnals of .Scottish Natural History " for July 

 contains a record of the fact that a roller, Coracias narrula. 

 was seen at Balnacoil, on the Brora, on May 28. The bird 

 was watched for several days, its favourite perch being the 

 end of the bare branch of a tree. 



Iceland Falcon in Lewis. 



Mr. J. .\. Ilaiviy Hrciuii writes to the " .\nnals of Scot- 

 tish Natural Hi-.tory " for July, to say that an Iceland 

 falcon, which had been watched during several days on the 

 Eye Peninsula, Lewis, was shot on February 28. 



Honey Buzzard in Fife. 



On May 21, according to tlie " ,\nnals of Scottish .Natural 

 History " for July, a honey buzzard " was unfortunately 

 shot " on the Largo Estate. It had apparently been see.i 

 hovering over a field in which young pheasants were being 

 reared. 



PHYSICAL. 



Bv Alfred W. Porter, B.Sc. 



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



Black-Footed Penguin Breeding in 

 Confinement. 



The small rookery of black-footed penguins, Spheniscu% 

 dcmrrsus, recently established in the gardens of the 

 Zoological Sociclv ol London, is thriving; so much so, that 



Radium and Electric Discharge in Tubes. 



A WAV ye.irs ago, Wehnelt showed that the dilTerence of 

 potenti.d required to produce a discharge through a vacuum 

 tube is \ery much diminished if liie cathode be coated with 

 an oxide of one of the metals of the alkaline earths, such 

 as barium oxide or calcium oxide, provided that the cathode 

 is then raised to a red heat by means of an independent cur- 

 rent. Mr. A. A. Campbell Swinton has quite recently 

 tested whether radium coated on the cathode produces the 

 same effect. Moreover, as radium gives off electrons when 

 cold, it was anticipated that it might be unnecessary to heat 

 the cathode. Using a cold cathode with a thin costing of 

 the bromide of radium, and with a continuous current 

 up to 400 volts pressure, this was found not to be the case. 

 .V very marked action in facilitating the production of a 

 luminous discharge was, howeverj observed when the 

 radium-coated cathode was healed ; in fact, a pressure of So 

 volts was then sufficient. Further experiments showed that 

 it is not sullicient that the radium be in the tube; it must 

 be on the cathode for the effect to occur. Whether the 

 radium salt is more or less efficient than barium or calcium 



