October, 1905.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



255 



White Tertiary Limestone at Heme Hill. 



In my collection are some pieces of hard white limestone 

 which I collected some time ago in what is now the end of 

 Rosendale Road, Heme Hill, when excavations were being 

 made for house-foundations. Tertiary limestones are, of 

 course, not unknown in our country, the Isle of Wight Oligo- 

 cene beds being instances. I do not remember, however, 

 having seen any reference to Eocene limestone in the neigh- 

 bourhood in question, and the point seems to be worthy of 

 record. Some of the rock was so hard as to have necessitated 

 the use of the pick and crowbar in its excavation, and 

 resembled the " Chalk Rock." Some portions were to some 

 extent siliceous, whilst others bore a close resemblance to 

 ordinary chalk. The stratum was fairly extensive, and. so far 

 as one can judge from the work of the Geological Surveyors, 

 it probably forms a stratum of the Woolwich and Reading 

 series. 



Mammals in the Wandle Valley. 



Amongst the Mitcham gravels the following Pleistocene re- 

 mains have been found, and are to be seen in the Croydon 

 TowQ Hall: Tooth of Mammoth Calf (E/cpIuis priinigeniiis) ; 

 tusk of ditto ; bones of Bos primigcjtii/s ; bones of horse (Eqiius 

 cahalliis). In the Thornton Heath gravels have been found 

 five teeth and numerous fragments of bones of Elephas priini- 

 i;i-nius. These are preserved in the Grange Wood Museum, 

 together with 5 feet of a tusk from the Mitcham gravels. 



ORNITHOLOGICAL. 



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

 Bird Outlaws in Norway. 



Birds of prey in Norway are apparently kept under with a 

 sternhand. Thei'"/V/i of August 26containsalist of carnivorous 

 mammals and birds upon whose heads a price is set by the 

 Government. Last year head-money was paid for 108 eagles, 

 130 eagle owls, 93 gyr-falcons and peregrines, 437 goshawks, 

 8S0 sparrow-hawks, and 1034 divers. We cannot congratulate 

 the Norwegians on the war of speedy extermination which 

 they are prosecuting. 



Montagu's Harrier in Northumberland. 



Mr. Abel Chapman, in the Field of September 2, writes to 

 protest against the " brutal and selfish " destruction of a 

 Montagu's Harrier (Circus cineraccus) on the Moors of Coquet- 

 dale, Northumberland, in August last. This bird, a female, 

 had apparently haunted these moors for some weeks only to 

 be shot at last by a game'.ieeper. Mr. Chapman writes with 

 some warmth on the matter, and we most heartily endorse 

 his remarks. 



Hen Hatrrier in Norfolk. 



A male and female hen harrier (Ciyciis cyancits) were shot 

 (Field, September 9) " during the last few months — the one at 

 Snettisham, the other at Wolferton — while quartering the 

 marshes." Both were immature birds. 



White Stork in Norfolk. 



The Field of September 9 records tlie occurrence of a white 

 stork (Ciconid alba) at North Wotton. Of course the bird was 

 shot, and proved to be an adult male in full plumage. 



Great Snipe in Shropshire. 



An immature specimen of this species is recorded by Mr. 

 E. G. Potter in the F(.7>/ of September g as having been shot 

 at Frees, near Whitchurch, Silop. The sex of the bird is 

 not stated, but the weight was 6 J o^s. 



Dusky Redshank in Kent. 



The Zooloi^ist for September records the shooting of a pair 

 of Dusky Redshanks (rof(7i(;(,s fusciis) at Jury's Gapp, Lydd, on 

 May 2g, both birds being in summer plumai^e. 



Squacco Heron in Kent. 



A specimen, fully adult (sex not stated), was shot in a grass 

 field at Rye, Sussex, according to the Zoologist for September, 

 on June 3. This makes the forty-first authenticated occurrence 

 of the species in Great Britain. 



PHYSICAL. 



By Alfred W. Porter, B.Sc. 



An Electrical Experiment. 



Professor Worthington, of the Royal Naval Engineering 

 College, Devonport, has recently tested whether any differ- 

 ence can be detected between space which is at a high electric 

 potential and space at a low potential quite irrespective of 

 the existence of any electric field in the space in question. 

 In explanation of this last proviso we nnay remind the reader 

 that electric force arises whenever there is a difference of 

 potential between two points; so that the absence of electric 

 force implies that the experiment must be so performed that 

 the electric potential has a uniform value. Use is ^made of 

 the fact that the potential inside a closed conductor is uniform. 

 Two such conductors, consisting of long tubes of semi-circular 

 section, were placed with their flat sides separated by a sheet 

 of ebonite only. These tubes were connected to the knobs of 

 a Wimshurst machine, and when the machine was excited the 

 space inside one of them would take a high positive potential 

 — practically uniform throughout it — whereas the other space 

 would have a much lower (or negative) uniform potential. 

 The experiment consisted in looking for a possible effect of the 

 potential upon the velocity of light. An ordinary interference 

 device was employed, i.e., light from a single source was split 

 into two beams, one of which passed down one tube, the 

 second down the other. These beams were then brought to- 

 gether again by a telescope lens, and in the overlapping region 

 interference bands are observed. If the effect of the high 

 potential is to increase the velocity of light then these bands 

 will shift. " When care was taken not to touch either table, 

 no shift whatever could be detected either when the spark 

 occurred or while the potential difference was accumulating." 

 The spark referred to was at the adjustable knobs of the 

 machine, which were kept i\ inches apart. This distance 

 determined the maximum difference of potential, viz., 60,000 

 volts; the length of the tubes was 152 cms. Assuming that 

 a shift equal to one-twentieth of a band could have been 

 detected if it had occurred, it follows from its absence that if 

 there is a difference of velocity it is less than sV^d of one- 

 millionth of the velocity itself. 



Ether-drift. 



Prof. Brace has recently extended the tests on a possible 

 influence of ether-drift on rotary polarisation using oil of 

 carraway seed instead of quartz, and concludes that the 

 effect of the motion of the earth on the rotation in active 

 substances is certainly less than one part in five million, 

 and probably less than one part in ten million of the total 

 rotation. 



The Future of Science. 



In an interesting article in the July number of the " Popular 

 Science Monthly," Professor Dolbear asks, " Is there no 

 more work for the man of science ? Are there no more 

 problems of importance awaiting the investigator ? Have we 

 all the knowledge we are likely to get ? There are some who, 

 having noted the prodigious product of the nineteenth cen- 

 tury, have half feared that science has been worked out." 

 We would point out that a glance at almost any scientific 

 journal should act as a tonic to any one who may be taking a 

 depressed view of the situation. It is not a distant retro- 

 spect that we must make in order to reach a period of scien- 

 tific prosperity. There probably never was a time in which 

 greater advances were being made than the present. Pro- 

 fessor Dolbear, however, is not himself a pessimist. He 

 asks the question merely as a preface to some suggestions of 

 his own as to future lines of research. We select one para- 

 graph only: "When the ether is understood we shall be able 

 to understand, in a mechanical sense, how moving a magnet 

 disturbs every other magnet wherever it may be ; why 

 chemical compounds are possible ; why crystals assume geo- 

 metrical forms ; and why cellular structure in plants and 

 animals can embody what we call life." 



