June ii, 1891] 



NATURE 



127 



Home Office for a licence or licences for vivisection on the 

 premises of the institute for some one or more of its members. 

 It seems to me that the Home Secretary would have fair ground 

 to complain of my action, if in a mailer of such admitted diffi- 

 culty, rousing as it does the strongest feelings of both sides, I 

 did anything which would enable you to go before him, to whom 

 Parliament has intrusted this subject, with the stamp of approval 

 as it were from another Government department which has 

 nothing to do with the subject at all. Now, I hope I have put 

 that shortly and plainly. What are your alternatives? You 

 have said something to me on this subject to-day. You can, of 

 course, if you choose, remove from your objects anything which 

 could bring you within the Cruelty to Animals Act, 1876. If 

 you did that, my objections would be entirely removed. You 

 could, if you chose, form yourselves as a Society, vesting your 

 property in trustees ; associate yourselves under the Companies 

 Act as a limited company, inserting a proviso that you should 

 pay no dividends. Now, I should like to have before me the 

 reasons in writing which have been urged to-day why none of 

 these courses would meet your views. I can only say in con- 

 clusion that I have endeavoured to put to you the difficulty 

 which I feel ; that I will carefully consider what has been said 

 to-day ; and any documents which the promoters of the Associa- 

 tion wish to place before me to enforce the views which have 

 been expressed I shall be glad to receive. 



Sir John Lubbock, in moving a vote of thanks to Sir Michael 

 Hicks-Beach, said that Sir Henry Roscoe had authorized him 

 to say that the further information which had been asked for 

 should be furnished to the Board of Trade. Vivisection was 

 after all a very small part of the question before them, unless, 

 indeed, vivisection was to be understood as applying to the 

 bacteria. He would venture to remind Sir Michael that although 

 Acts of Parliament might orevent them from destroying the 

 bacteria, they could not prevent the bacteria from destroying 

 human beings, and it seemed almost a significant fact that no 

 members of the community, as he knew to his own cost, had 

 suffered more from them than members of the House of Com- 

 mons. He had no reason to suppose that bacteria suffered at 

 all, though human beings suffere i very much from the bacteria. 

 The bacteria were now experimenting upon them, and all that 

 they asked was that they should be allowed to defend themselves 

 from the bacteria. Something had been said about agriculture, 

 and he believed that such an institute as this would add much 

 to the prosperity of agriculture and probably of manufactures 

 and of commerce. As regarded the technical points which had 

 compelled the right hon. gentlemin to adopt the course which 

 he had taken, he thought if Sir Michael went into the matter 

 he would find at least two precedents in which an opposite line 

 had been taken in cases where vivisection was practised. 



The President — I ought to mention that any of the prece- 

 dents which have been mentioned I should like to have placed 

 before me. 

 The deputation then withdrew. 



EARTH-CURRENTS AND THE ELECTRIC 

 RAIL WA V. 



A WELL-MARKED case of interference with the 

 -^*- earth-currents recorded at the Royal Observatory, 

 Greenwich, due apparently to the working of the new 

 Electric Railway, having recently been experienced, of 

 which some account might prove to be interesting to 

 electricians, the Astronomer-Royal has kindly allowed 

 me to communicate for publication in NATURE some 

 particulars in regard thereto. 



It is known that for many years past a continuous 

 photographic register of earth-currents has been main- 

 tained at the Royal Observatory. There are two circuits. 

 For one circuit the earth-plates are at Angerstein Wharf 

 (A.W.), on the southern bank of the River Thames, near 

 to Charlton, and at Lady Well, Lewisham (L.W.) ; for 

 the other circuit the earth-plates are on Blackheath (B.), 

 at the south end of the North Kent Railway tunnel, and 

 at the North Kent East Junction (N. K.E.J.) of the 

 .South- Eastern Railway, the junction of the North Kent 

 and Greenwich lines. The earth connection is in each 

 case made by an independent copper plate ; these plates 



NO. II 28, VOL. 44] 



are used only for the earth-current lines, no other wires 

 being attached thereto. From the A.W. earth-plate the 

 wire passes by the South-Eastern Railway lines to the 

 Greenwich Station, thence underground to the Royal 

 Observatory recording apparatus, returning underground 

 to the Greenwich Station, and thence by the railway to 

 the earth-plate at L.W. Similarly for the Blackheath- 

 North Kent East Junction circuit. The direct distance 

 between the A.W. and L.W. earth-plates is 3 miles, and 

 between the B. and N. K.E.J, earth-plates about 2| miles. 

 The azimuth of the A.W.-L.W. line, reckoning from 

 magnetic north towards east, is 50° ; the azimuth of the 

 B.-N. K.E.J, line, reckoning from magnetic north towards 

 west, is 46°. Registration is effected in the usual way. In 

 each circuit there is a horizontal g.ilvanometer the needle of 

 which carries a small mirror ; on this the light from a 

 fixed gas-lamp falls, and, reflected therefrom, finally 

 reaches the revolving cylinder as a small spot of light. 



Some few particulars concerning earth-current motions 

 generally may perhaps be given. It has been found that 

 all cases of disturbance of the magnets are accom- 

 panied by earth-currents, more or less powerful as the 

 magnetic disturbance is more or less pronounced. The 

 correspondence is most complete. No sudden marked 

 motion of the magnets ever occurs without corresponding 

 active earth-currents, as may be seen by the plates (copies 

 of the various registers) given in the several Greenwich 

 volumes since the year 1882. On days on which the 

 magnets are free from disturbance, and show only the 

 ordinary diurnal change, earth-currents are very feeble. 



Before speaking of the recent case of interference, we 

 may devote a few words to the description of a previous 

 case in which the interference was much less marked in 

 character, although, with some intermissions, otherwise 

 very persistent. Some five years or more ago it was re- 

 marked, in the A.W.-L.W. register, that at one part of 

 the day a slight dislocation of the trace occurred, in no 

 case indicating a change of potential of more than o*l 

 volt, frequently much less : after some hours the trace as 

 suddenly returned to its normal position. This was not 

 discernible every day, but still frequently, and still con- 

 tinues. Nothing has been perceived in the other circuit. 

 On examining the A.W.-L.W. records for a number of 

 months, it appears that at all parts of the year the dis- 

 location occurred some thiee-quarters of an hour after 

 sunset, and the return to normal position at about the 

 same interval before sunrise. The cause of the interfer- 

 ence has not been traced, although it has been conjec- 

 tured that in some way it may be connected with electric 

 lighting in the vicinity of the A.W. earth-plate. 



We now come to the recent much more serious case of 

 interference. Towards the end of last year anomalous 

 appearances began to be observed in both of the earth- 

 current registers, not continuously but in a somewhat 

 irregular manner. Now, however, for some months past, 

 these new interruptions have settled down into a regular 

 order. What is perceived is that the interference in 

 question, causing a continuous vibration of the registering 

 needles, commences shortly before 7h. in the morning, 

 goes on all through the day, terminating shortly after 11 h. 

 in the evening. This went on for several months on 

 week-days only, ceasing on Sundays, nothing being seen 

 after iih. p.m. on Saturday, until yh. a.m. on Monday. 

 But on Sunday, April 5, and on every succeeding Sunday 

 to the present time, the interference has been experienced 

 also on a portion of the Sunday, commencing at about ih. 

 p.m., and terminating usually at loh. p.m. or shortly after- 

 wards. Various experiments were made with the view of 

 discovering the cause of these anomalous appearances, 

 but without definite result. Quite recently, Mr. 

 Leonard, the telegraphic superintendent of the South- 

 Eastern Railway, to whom the Observatory is much 

 indebted for considerable assistance in many matters 

 connected with the earth-current work, was led to suggest 



