20 



NA TURE 



[November i, i >oo 



production. In the case of silver, of which the world in 1898 

 produced 165,000,000 ounces, Mexico produced 34*4 percent., 

 the United States 33 per cent., and Australasia 7*3 per cent. 

 Less than half the world's supply was obtained from silver ores. 

 The remainder was obtained from the metallurgical treatment 

 of other ores in which silver was an accessory constituent. 

 Since those ores would continue to be mined for the other 

 metals they contained, a steady supply of silver was assured, 

 whilst a slight rise in the price of silver would enable many 

 deposits of true silver ores now untouched to be worked. 



In a paper read before the Society of Arts in 1854, Mr. J. K. 

 Blackwell stated that the world's production of pig iron then 

 amounted to 6,000,000 tons. Of that quantity the United 

 Kingdom produced 50 per cent., France 12 '5 per cent., the 

 United States I2'5 per cent., and Germany 6 "6 per cent. In 

 1898 the world's production had risen to 35,741,000 tons, of 

 which the United States produced 327 per cent., the United 

 Kingdom 24T per cent., Germany 20"6 per cent., and France 

 7 "I per cent. The relative position of the different countries 

 from a mining point of view, is better shown by the statistics of 

 iron ore production. The world's production in 1898 was 

 73,670,000 tons, of which the United States produced 26*2 per 

 cent., Germany 21*6 per cent., the United Kingdom 19 "3 per 

 cent., Spain 97 per cent., France 6 "2 per cent., Russia 5 "6 per 

 cent., Austria-Hungary 4'5 per cent., and Sweden 3'i per cent. 

 Tlie more important iron ore deposits now worked are at the 

 mines of Lake Superior, Bilbao, Southern Spain, the Ural, 

 Styria, Dannemora, Grjingesberg and Gellivare. 



With regard to copper, the rapid decadence of British copper 

 mining was owing to copper in the Cornish mines having given 

 p'ace to tin as greater depths were reached, and to these great 

 depths and the quantity of water encountered rendering competition 

 with the American and Spanish deposits impossible. There are, 

 however, large areas unexplored, and many mines worth re-open- 

 ing should the price of copper rise, and should the disadvantages 

 experienced in Great Britain make themselves felt abroad. 

 Owing to the increased demand for copper caused by the rapid 

 .extension of the applications of electricity, a further rise in 

 iprice is not improbable. The world's production of copper in 

 1898 was 424,126 tons, of which amount tlie United States pro- 

 duced 55'i per cent., Spain and Portugal I2'6 per cent., Japan 

 .5-9 per cent.. Chili 5*8 per cent., Germany 4*9 per cent., Aus- 

 tralasia 4*2 per cen;., Mexico 2*5 per cent., Canada i"9per 

 •cent., Cape Colony i'6 per cent.., and Russia i"4 per cent. 

 Last year the world's copper production was about 474,000 

 tons. The Anaconda Mine produced 1 1 per cent, of the world's 

 •output, and among other important copper mines are those in 

 Arizona, in the Lake Superior district, in the South of Spain 

 ((Rio Tinto and Tharsis), and Portugal (San Domingos), in 

 ijouth America, in Japan; at Mansfeld,and at the Rammelsberg, 

 in Germany ; at Falun, in Sweden ; and in Australasia (Mount 

 Lyell, Tasmania ; Moonta and Walleroo, South Australia ; and 

 Great Cobar, New South Wales). 



CONFERENCE OF DELEGATES OF CORRE- 

 SPONDING SOCIETIES OF THE BRITISH 

 ASSOCIATION. 

 'T'HE first meeting of the Conference took place at Bradford 

 on Thursday, September 6. 



The report of the Committee, a copy of which was in the 

 hands of every delegate present, was taken as read. The chair- 

 man then remarked that the chief subject for discussion that day 

 'consisted of the following resolutions, which had been brought 

 forward by the Yorkshire Naturalists' Union : — 



(i) That the Conference of Delegates be allowed to meet on 

 the first day of the British Association meeting, and make their 

 own arrangements for subsequent meetings and order of 

 business. 



(2) That it is desirable, in order to make the discussions of 

 the Conference of Delegates more useful to the local societies, 

 that they should have the power of deciding the subjects for 

 discussion at the meetings of the Conference, and it is sug- 

 gested, therefore, that a circular be sent by the Committee every 

 year to each of the corresponding societies asking them to send 

 a list of subjects for discussion (not more than two or three) at 

 the forthcoming meetings. The Committee then to send to the 

 corresponding societies a schedule containing the titles of all 

 the subjects proposed for discussion, asking each society to mark ' 



NO. 1 61 8, VOL. 63] 



such of these subjects as it deems most desirable to discuss at 

 the Conference meetings. On receipt of this- information the 

 Committee will then arrange the list of subjects in order of 

 precedence as indicated by the support given to each subject by 

 the societies ; and a copy of this should be sent to the delegates- 

 or Societies as an agenda paper before the first meeting of the 

 delegates. 



After a long discussion, it was resolved that the meetings of 

 the Conference be held on Thursday and Tuesday, as heretofore. 



Copyright. — Mr. Walton Brown remarked that some time ago 

 Lord Monkswell had introduced a Bill into Parliament dealing 

 with copyright, but so far as scientific societies were concerned 

 the Bill ignored some important points. There was no provision 

 that a society should have any copyright in the publication of 

 its own transactions. He believed that societies could claim 

 copyright if they paid their contributors. He thought that the 

 Conference should ask the Corresponding Societies Committee 

 to take steps to have an amendment proposed recognising the 

 copyright of scientific societies in their publications. 



Prof. Henry Louis pointed out that the British Association 

 expressly disclaimed copyright for themselves ; and the Rev. 

 J. O. Bevan urged that a special case should be prepared and 

 submitted to counsel for a legal opinion. Mr. Walton Brown's 

 views were unanimously accepted by the meeting, which then 

 adjourned. 



At the second meeting of the Conference an address on dew- 

 ponds was given by Prof. Miall. In the first place, Prof. Miall 

 noticed the mention of dew-ponds by Gilbert White (" Natural 

 History of Selborne," Letter Ixxi.), and more recently by the 

 Rev. J. C. Clutterbuck in a prize essay on " Water Supply." 

 Both writers described them as existing on the tops of chalk hi Us, 

 and Mr. Clutterbuck says that at the selected spot an excavation 

 is made from 30 to 40 feet or more in diameter, and from 4 to 

 6 feet deep. The bottom is covered with clay mixed with lime, 

 and a layer of broken chalk is placed over the clay with lime to 

 prevent injury to this impermeable lining. Water is then intro- 

 duced by artificial means. If there is a fall of snow this is 

 collected and piled in the pond. Ponds so made have be^n 

 known never to become dry during periods of twenty or thirty 

 years. They are most common on the chalk hills of Sussex and 

 Hampshire, and are also found in Berkshire and Wiltshire. But 

 on the chalk of Hertfordshire, Bedfordshire, Lincolnshire and 

 Yorkshire there are few or none. 



As dew-ponds often occupy the summit of a ridge so precisely 

 that they can have no collecting ground worth mentioning, and 

 as any springs are hundreds of feet below, it becomes an 

 interesting question why they retain more or less water when 

 the low-level ponds of the same district have become dry, 

 though they supply water for large flocks of sheep. 



Prof. Miall then reviewed the evidence bearing upon the 

 question whether these ponds are mainly dew-ponds or rain- 

 ponds, and quoted the experience of Mr. Clement Reid, who 

 found that at the end of a long drought the best dew-ponds were 

 sheltered on the south-west side by an overhanging tree, or the 

 hollow was sufficiently deep for the south bank to cut off much 

 of the sun. The depth or shallowness of the water did not 

 appear to make so great a difference as might be expected. 



It was, however, evident that many additional observations 

 were necessary before this question could be settled. It was 

 desirable that the temperature of the water of the pond at 

 various depths, as taken hourly through a summer night, should 

 be noted, and that many other thermometrical observations 

 should be made. He concluded by asking that residents in the 

 south-eastern counties would investigate the matter. 



Mr. Clement Reid had been working for some years in a 

 country where dew-ponds were abundant, but did not think 

 they were formed in the scientific manner pretended by their 

 makers. In times of drought some dried up and others did not, 

 the fittest surviving. Farmers were continually making new 

 ones, and sometimes, by accident, hit on a satisfactory site It 

 was unfortunate that they were almost entirely without meteoro- 

 logical observations on the high ground where dew-ponds might 

 be seen. 



Mr. Hopkinson noted the difficulty of ascertaining the amount 

 of water contributed to the pond by dew. A distinction must 

 be drawn between dew and mist. There were scarcely any 

 rain gauges on the high ground where dew-ponds existed, 

 though probably more rain fell there than in the valleys. He 

 did not know of any dew-ponds in Hertfordshire. Mr. J. Brown 

 and Mr. W. Gray stated that there were no dew- ponds in Ire- 



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