470 



NATURE 



[September io, 1908 



the most complete memoir on the subject, and is of special 

 interest at the present time, when growing uneasiness 

 prevails that many of the world's best tin deposits are 

 becoming: exhausted, and that the price of the metal may 

 possibly become quite prohibitive for many industrial pur- 

 poses before long. In Bolivia it is evident that the pro- 

 spects are good. That country now ranks second only to 

 the Federated Malay States as a tin-producing district, 

 and it is probable that the production will continue to 

 increase. Careful exploration has been made in Peru in 

 the provinces of Huancan^ and Chucuito, which are the 

 nearest to the Bolivian tinfields, but with the exception 

 of some samples of stanniferous lead ore found at Vilque 

 Chico, no indications of tin were discovered. .■\nother 

 Boletin (No. 56) issued by the Corps of Mining Engineers 

 of Peru deals with the problem of the irrigation of the 

 valley of lea. 



The records of the Mysore Geological Department 

 {vol. vii.), which have just been received, contain general 

 and special reports of work done from July, 1905, to June, 

 1906. The year was an eventful one in the history of 

 mining in Mysore owing to the attention devoted to the 

 mineral resources by European and native capitalists. 

 •Chipf among the ores sought were those of manganese 

 and chromium. Other minerals which engaged attention 

 were magnesite, asbestos, and chromium. The new gold- 

 field near Lingadhalli gave good indications. The value 

 of the gold raised in the Kolar area during the year was 

 2,274,786!. The results of the work of the Geological 

 Survey during the year are given in special reports by Mr. 

 H. Kelsall Slater and Mr. P. Sampat Iyengar. The former 

 made a geological survey of 180 square miles in the Kadur 

 district. The boundary of the granite extending from 

 Tarikere westward was mapped, and found to conform 

 generally with the base of the hills. The schists com- 

 posing the hills are invariably associated with the occur- 

 rence of gold. Numerous old workings were discovered, 

 and the area deserves careful prospecting, as it bids fair 

 to prove another valuable goldfield. In the Mysore district 

 the felsite and porphyry dykes of Seringapatam were 

 mapped. In the Tumkur district traces of gold were 

 found, and the native workings of grey corundum are de- 

 scribed. Reports are also given on the geology of the 

 Srinivaspur and Kadri Taluks, and of parts of Challakere 

 and Sira Taluks. An appendix is devoted to a detailed 

 description of important felsite and porphyry dykes in the 

 neighbourhood of Seringapatam. When polished they yield 

 very handsome ornamental and building stones. 



In his " Studies on the Thermodynamics of the Atmo- 

 sphere," published under the auspices of the Weather 

 Bureau, U.S. Department of Agriculture, Prof. F. H. 

 Bigelow collects nine papers which he had contributed 

 during 1906 to the Monthly Weather Review. They deal 

 with a variety of subjects, including the meteorological 

 conditions characteristic of different parts of cyclones and 

 anticyclones in Europe and America during summer and 

 winter. The temperature gradient at different levels 

 receives special attention* The last four papers deal with 

 a waterspout, or waterspouts, seen near Cottage City, 

 Mass., in August, 1896. In most of the papers, even 

 those relating to the waterspout, there is a rich profusion 

 of statistical data, conversion factors, and mathematical 

 formulae. There are sixty-seven tables and forty illustra- 

 tions, including ten full-page photographs of the Cottage 

 ■City waterspout at different stages of development. A 

 large number of conclusions are also drawn. The papers 



NO. 2028, VOL. 78] 



provide evidence of industry and imagination, and the 

 conclusions and observational data will no doubt receive 

 the critical examination of meteorologists. 



A CORRESPONDENT has Written to point out that Prof. 

 von Thdn, to whose memory a monument is to be erected 

 at O-Becse, Hungary (see Nature, August 27), held the 

 chair of chemistry from 1S62 in the University of Buda- 

 pest, and not that of the University of Vienna. 



OUR ASTRONOMICAL COLUMS'. , 



Discovery of a Comet, igoSc. — A telegram received 

 from the Kiel Centralstelle announces that a new comet i 

 was discovered by Prof. Morehouse, of the Drake Uni- 

 versity Observatory, Des Moines, Iowa (U.S.A.), on 

 September i. At 8h. 40m. (Yerkcs M.T.) on that date 

 the position of the comet was 



R.A.=3h. 20m., dec. = 66° 15' N., ; 



and it was reported as moving rapidly in either a south- 

 east or north-west direction. It was also said to possess 

 a long, conspicuous tail. 



A second telegram states that this object was observed 

 by Prof. Thiele at Copenhagen on .September 3, its posi- 

 tion at loh. 29-6m. (Copenhagen M.T.) being 



R.A. =3h. 19m. 43s., dec. = 67° 14' 42" N., 



so that the motion is north-west. This observation gave 

 the magnitude of the comet as 9-0. The present apparent 

 path lies through Cassiopeia towards Cepheus, and the 

 comet does not set below the horizon in London ; it reaches 

 the zenith about 4 a.m., and should therefore be an easy 

 object for telescopic observation. 



The comet was quite easily found with a 3:i-inch 

 equatorially-niounted finder at South Kensington on 

 Friday night, September 4, and in the lo-inch refractor, 

 with a power of 100, appeared as a very diffuse, nebulous 

 patch with scarcely a trace of any stellar nucleus. 



Large Sun-spots. — The large sun-spots illustrated in 

 these columns in our issue of August 13 have again 

 appeared round the eastern limb of the sun. They were 

 first re-observed at South Kensington on August 27, and 

 have since been visible to the naked eye. On August 29 

 a new, large spot followed, and on September i the large 

 group, two large single spots, and a smaller group were 

 to be seen on the disc. For the actual epoch of solar 

 activity the disc is, therefore, displaying a remarkable 

 amount of spotted area. 



Recent Meteors. — Some interesting notes on meteors 

 recently observed are published by Mr. Denning in 

 No. 400 of the Observatory (p. 350, September). Mr. 

 Denning remarks on the favourable conditions for meteor 

 observations that obtained during the present summer, 

 and states that on fifteen dates between July 18 and 

 August 8 he observed 204 meteors during 205 hours. Of 

 these, more than half were traced to known radiants, 

 forty-two of them being Perseids. During the period 

 July 26 to August 7, the Perseid radiant moved from 

 2.S°. +53°. to 41°, -(-56°; a late Perseid was seen, on 

 .August 17 at qh. 25m., which left a fine streak, and was 

 directed from 51°, +58°; another, of the first magnitude, 

 was seen on August iqd. gh. 44m., and its direction was 

 from a point at 56°. -|-6o°. 



For the period June 25 to August 10, Mr. Denning 

 received duplicate observations of ten meteors, for which 

 hr gives the particulars of the real paths. 



D, (Helium) Absorption in the Solar Spectrum. — In 

 n letter to the Observatory (No. 400, September, p. 353) 

 Captain Daunt reports that he believes he observed D, 

 dark in the solar spectrum when making visual spectro- 

 scopic observations of the large sun-spot group which 

 was near the eastern limb on August i. The line had 

 much the same appearance as that shown on the photo- 

 graph taken by Mr. Nagaraja at Kodaikdnal last year, 

 running as a fairly fine dark line, somewhat thickened 

 in the centre, right across the group. Although the sun 



