158 



NA TURE 



[June 14, 1906 



The report for rqo5 of the Botanical Exchange Club of 

 the British Isles, prepared by Mr. J. W. White, has been 

 received. Besides being the official organ for the publi- 

 cation of notes by the collectors or special authorities on 

 the correct determination of the plants, the report provides 

 a record of new or rare species with the localities in which 

 they have been found. The new records include Caltha 

 nidicnns for Perthshire, Ulex Gallii, var. huinilis, for Corn- 

 wall, the aliens Hibiscus Trionum and Bromus unolioides 

 collected in Salop, Lotus tenuis from near Cardiff, and 

 Epipactis atrorubens from Banff. The specific determination 

 of the large-flowered Qinothera so plentiful on the Lanca- 

 shire coast having been questioned, Mr. C. Bailey sent 

 specimens to Dr. O. Focke, of Bremen, who considers that 

 it is probably a form of the famous variable CEnolhera 

 Lamarckiana. 



The Home Oflice has issued for 1905 statistics of the 

 persons employed, output, and accidents at mines and^ 

 quarries in the United Kingdom, arranged according to the 

 inspection districts. The total number of persons employed 

 was 887,524, of whom 858,373 worked at the 3252 mines 

 under the Coal Mines Act and 29,151 at the 688 mines 

 under the Metalliferous Mines Act. At the quarries under 

 the Quarries Act there were 94,819 persons employed. The 

 death-rate from accidents was 149 per 1000 persons em- 

 ployed for coal miners and 2-49 per 1000 for metal miners. 



We have received the two latest additions to the valuable 

 series of bulletins issued by the Peruvian Corps of Mining 

 Engineers. In Boletin No. 30 Mr. Carlos E. Velarde gives 

 a detailed account of the means adopted to obviate acci- 

 dents in the mines of the Cerro de Pasco. Boletin No. 31 

 is a monograph on the mineral resources of the province 

 of Cajamarca, by Mr. F. Malaga Santolalla. The work 

 covers eighty-three pages, and is well illustrated and 

 furnished with maps and sections. The coalfields of the 

 province are of considerable importance, bituminous coal 

 being worked at Yanacancha and anthracite at Punre. 

 Descriptions are also given of mines of silver-lead ores, 

 of copper, antimony, and sulphur. In fact, the province 

 is one of exceptional mineral wealth. 



Messrs. Swan Sonnenschein .and Co., Ltd., have pub- 

 lished a second edition of Mr. C. H. Hinton's book on the 

 fourth dimension. The first edition was reviewed in the 

 issue of Nature for July 21, 1904 (vol. Ixx., p. 269), and 

 it is only necessary to say that the new edition differs 

 chiefly by the addition of a new chapter of twenty-three 

 pages on a language of .space. The new chapter is also 

 published separately. 



) and February 27, 1906, 

 of the Mont'hlv Notices 



OUR ASTRONOMICAL COLUMN. 



Photographing the Corona without a Total Eclipse. 

 —A communication from MM. Millochau and Stefanik 

 referring to a recent note in these columns (May 31, p. 112) 

 on their proposed method of photographing' the' corona 

 without a total eclipse of the sun points out that the 

 meaning of part of their note in the Comptes rcndus was 

 misinterpreted. 



The successful experiments at Meudon dealt with the 

 feasibility of photographing the line at A 5303 with a 

 spectrograph ; and others, performed since their communi- 

 cation to the academy was published, have clearly affirmed 

 the possibility of observing the green coronal line' when the 

 atmosphere is sufficiently pure and suitable screens are 

 employed. It is this study of the spectrum of the corona 

 that they hops to complete on the summit of Mont Blanc. 



Observations of Nova Geminorum. — The results of 

 some interesting observations of Nova Geminorum, which 

 were made by Prof. Barnard between the date ' of the 

 NO. 191 I, VOL. 74] 



Nova's discovery (March, 191 

 appear in No. b, vol. Ixvi 

 (R.A.S.). 



At the time of discovery the magnitude of the Nova was 

 8-0, but it steadily decreased until at the present time the 

 object is but very little brighter than the fifteenth-magni- 

 tude star which slightly precedes it. 



The observations made in order to discover any possible 

 difference of focus between the Nova and the surrounding 

 stars indicated no such difference at first, but on September 

 21, 1903, it was found that the focus for the Nova was 

 0-29 inch further from the object-glass than that of a tenth- 

 magnitude preceding white star. In connection with these 

 observations a curious feature was noted on March 30, 

 1903. The Nova appeared to have two distinct foci, both 

 of which gave sharp images. The one image was of about 

 85 magnitude, of reddish-yellow colour, and at the 

 ordinary stellar focus, whilst the second was of the tenth 

 magnitude, about 0-39 inch further out, and of a beautiful 

 crimson colour. On April 6 the crimson image was still 

 present, though not so strong or definite, and on April 27 

 it had entirely disappeared. This image was probably due 

 to the strong Ha line in the spectrum of the Nova. 



Measures of the distances between the Nova and the 

 surrounding comparison stars, of which Prof. Barnard 

 gives a chart, indicate a decrease of distance between one 

 of the latter and the Nova. From this it would appear 

 that the Nova is in motion, but that cannot be stated as 

 a fact until further measures have been made. The 

 measures of the position of tlte Nova gave no indication of 

 a parallax. 



Personal Equation in Photometric Observations. — In 

 No. 4089 of the Astroiioniische Nachrichten Prof. Ceraski 

 directs attention to the fact that in recording the results of 

 observations made with the Zollner photometer it very 

 often happens that no mention is made of the relative 

 positions of the real and the artificial stars during the 

 observation, and asks that this should always be carefully 

 recorded by the observer. 



There is often an effective personal equation introduced 

 into the results, depending upon whether the real star is 

 to the right or to the left of the artificial star when the 

 observation is made, and as this equation varies with the 

 instrument employed and the magnitude of the variable 

 star at the moment of observation, it becomes important 

 that the conditions should be carefully recorded and the 

 resulting corrections applied when the final values are 

 computed. 



Comet igobfe (Kopff). — In No. 4087 of the Astronomische 

 Nachrichten Herr M. Ebell publishes a newly derived set 

 of elements and an ephemeris for comet igoOb. The 

 following are the elements : — 



T= 1905 Oct. 186620 (Berlin M.T.) 

 ce = i58°42' ll"-4"| 

 « =342° i.V 35"'i -1906-0 

 i = 4° 14' 32" -4] 

 log r; =0-522130 



The ephemeris shows that the comet has just passed 

 from the constellation Leo, wherein it was discovered on 

 March 13, into \'irgo, and is situated about one-third of 

 the distance between v Leonis and Virginis, reckoning 

 from the former. 



A note in the Observatory (No. 371) points out that the 

 perihelion distance of this comet is greater than any 

 previously recorded, with the exception of that of the 

 comet of 1729. Prof. Wolf has found an image of the 

 comet on a plate secured on January 14, 1905, more than 

 a year before the discovery, an event which is unique in 

 the history of cometary observations. At that time the 

 magnitude of the object was about 0-4 that at the time of 

 discovery, and approximately equal to the present magni- 

 tude. 



Observations of Variable St.ars. — Twenty-two newly dis- 

 covered variable stars in Carina are announced in Circular 

 No. 115 of the Harvard College Observatory. The vari- 

 ability of these stars was discovered by Miss Lcavitt from 

 the examination of six plates taken with the Bruce tele- 

 scope, the total number of variables discovered from these 

 plates being now thirty-nine. The star H 1232 is found lo 



