io6 



NATURE 



\_Dec. 4, 1879 



monograph enable us to trace the numerous and rapid 

 changes which these carboniferous strata undergo within 

 comparatively limited areas. The manner in which the 

 several members of the series overlap one another, as has 

 already been pointed out by Mr. Davies, is also admirably 

 illustrated in this work of Mr. Morton's. 



Perhaps no part of this excellent memoir will prove of 

 more general interest to geologists than Mr. Morton's 

 account of the numerous faults which traverse the district ; 

 the positions and effects of these being illustrated by a 

 map and several sections. The isolated patch of car- 

 boniferous rocks faulted down among the Silurian strata 

 near Corwen is also more fully described than by any 

 previous author. Besides the numerous woodcuts and 

 lithographic plates, the work is illustrated by three ad- 

 mirable photographs by Mr. W. H. Wilson. We heartily 

 recommend this exhaustive monograph to the attention 

 of our readers, as a model of the kind of work which may 

 be advantageously undertaken by the members of local 

 scientific associations. J. W. J. 



Magnetism. The High School Series. (London : T. 



Murby, 1879.) 

 The anonymous author of this little work of sixty-eight 

 pages has produced a very readable and in many ways 

 admirable primer of Magnetism for boys and girls. 

 Clearly written, well illustrated, and dealing with such 

 matters of experiment as boys and girls can verify for 

 themselves, it will be sure to command popularity. The 

 experiment on p. 22, which suggests the form of the curve 

 of magnetic intensity along a bar-magnet by the length of 

 the chain of nails which can be hung on at equidistant 

 points, thus building up visible ordinates on the abscissa? 

 is new to us, and as neat as novel. One cannot help 

 wondering, however, why the author has assumed that 

 "high-school'' pupils must have mathematics and even 

 arithmetic kept almost entirely out of sight. Why the 

 separate chapters are entitled as " Lectures" is not very 

 evident. The "Lecture," for example, on " Diamag- 

 netism" — the ninth of the ten — is just thirty-seven lines 

 long, and takes just two minutes to read aloud ! 



LETTERS TO THE EDITOR 



[The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, or 

 to correspond with the writers of, rejected manuscripts. No 

 notice is taken of anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure on his space is so great that it 

 is impossible othenvise to ensure the appearance even of com- 

 municalions containing interesting and novel facts.] 



To Astronomers 



I HAVE the honour to inclose to you a copy of a circular which 

 I have lately sent out from my ob ervatory to upwards of 200 

 observatories, public and private, scattered over the face of the 

 globe. I have long felt that it was highly desirable that some 

 means should be found whereby the di coveries in astronomy 

 should be made public in a rapid and systematic manner, more 

 especially in this country, where I am proud to say we number 

 so many among all clas-es who take an intelligent and earnest 

 interest in this the highest of the studies of nature. After much 

 thought as to the best means of carrying out the plan, I deter- 

 mined, it may be presumptuously, to endeavour to do the work 

 myself, and to that end I issued the circular to all directors of 

 observatories whose addresses I ould lay my hands upon. 

 Should I have the fortune to receive favourable replies from 

 abroad, I hope to make the matter successful. Now as to the 

 distribution of the news in the British Islands : I am making a 

 list of those who apply to me for the circulars and I will endea- 

 vour to post these within 24 hours of receiving the notice myself . 

 I have made arrangements with the telegraph officials, that any 

 telegram addressed (as below) shall be sent out at whatever hour 

 it may arrive : I have further set up a small printing press in my 

 observatory from which to pull the circulars, as I feel sure that 

 this is the most convenient method and the least liable t) error. 



In conclusion I may add that should any device a better means 



for doing this work, I will at once place my experience at their 

 disposal and do all I can to assist them. LINDSAY 



Haigh Hall, Wigan, 

 November 29 



" The Observatory, Dun Echt, Aberdeen, 



" November I, 1879. 



"Sir, — I am very anxious to form some system whereby 



information of astronomical interest may be rapidly and widely 



disseminated among English observers ; and I would beg to ask 



for your assistance in carrying out my plan. 



" In the event of your discovering a comet, new star, or other 

 object of immediate interest, I would ask you to send me a tele- 

 gram announcing the discovery and giving such details as are 

 usual. 



" I have purposely omitted to mention minor planet disco- 

 veries, inasmuch as this branch is already admirably carried out 

 by the Berlin Ob-ervatory. 



" For convenience, the telegram should be in the form recom- 

 mended by the Vienna Academy in the 75th vol. of the Astr. 

 jVachr., No. 1785, page 142, as follows : — ' Comet (new star, 

 &c.,) Discoverer, Date, Local Mean Time of Observation (in 

 hours and minutes), Place of Discovery, Right Ascension in Arc 

 (degrees and minutes), North Polar Distance (degrees and 

 minutes), Daily Motion in R.A. and N.P.D. (minutes of arc) 

 plus or minus, Description, Diameter of Comet, &c. (in minutes 

 of arc). 



' ' Thus a telegram would run : — 



" 'Comet Winnecke 5 April. 1445 Strassburg 3315" 

 0750S Motion o minus 60.' 

 " This would read : — 



" ' Comet discovered by 'Winnecke, 5th of April, 14 

 hours 45 minutes Mean Time Strassburg, R.A. 

 331° 57', N.P.D. 75 8'. Daily Motion, stationary 

 R.A., minus 60' in Polar Distance.' 

 " Noughts should be put in where are no significant figures, so 

 as to make three figures for degrees, and two for minutes (five in 

 all), in R.A. and in N.P.D., similarly four in the Local Time. 

 " Telegrams, &c, should be addressed — 

 " ' Observatory, Dun Echt, Aberdeen.' 

 " I will engage to distribute the notices of discovery within 24 

 hours of receiving the telegram, by means of a circular, sent out 

 by first post from my Observatory, to all those who would be 

 likely to make useful observations, and who will also favour me 

 with their addresses. 



" At present, it is only by accident that private observers hear 

 of the discovery of Comets, &c, and it is obviously greatly to 

 the advantage of astronomy that early and reliable information 

 should be spread over the British Islands, without having to wait 

 for its publication in some of our scientific journals. 



" I should feel much gratified if I may feel assured of your 

 valuable co-operation in this matter. 



" Believe me, yours very faithfully, 



" Lindsay, 

 " Pres. Roy. Ast. Soc." 



The Cresswell Cave Exploration, 1876 

 It seems to me proper to notice the statements made by Mr. 

 Heath in a pamphlet on the bone-caves of the Cresswell Crags, 

 published in August last, and since more broadly put in the 

 Manche.-ter press, calling in question the results of the explora- 

 tion carried on by the Committee in 1876. 1 



It is insinuated that the engraved bone now in the British 

 Museum, discovered by the Rev. J. M. Mello, and the tooth of 

 Machairodus, discovered by myself, are not bon&ftdt discoveries 

 in the caves of the Cresswell Crags, but were placed there by 

 some one, not specified, and were derived from some other loca- 

 lity, which also is not specified. With regard to the engraved 

 bone, it is only necessary to say that Mr. Heath was not in ths 

 Robin Hood Cave when Mr. Mello's discovery was made, while 



1 Committee :— President: Sir J >hn Lubbock, Cart.. F.R.S.. M.P. Secre- 

 tary : Prof. Boyd Dawkins, M.A., F.R.S. Treasurer: I- redk. Longden, 

 Esq. Members: Prof. Busk, F.R.S. ; Prof. Prestuich, F.R.S.; John 

 Evan,. Esq., F.R.S.; A. W. Franks, Esq.. F.R.S.; the Rev. J. Magen* 

 Mello, M. A.. F.G.S. ; Rooke Pennington. Esq.. LL.B., KG.S ; William 

 Bragge, Esq., F.G.S. ; R. D. Darbishire, Esq., B.A., I .G.S. The work is 

 under the direction of the Rev. J. M. Mell .. Prof. Boyd Dawkms and Mr 

 Heath. F.R.H.S , being superintendents, 'the Report will be prepared for 

 the Geolcg'.cal S c.ety of London by the Rev. J. M. Mello and Prof. Boyd 

 Daivkins. 



