450 



NA TURE 



[September 5, 1901 



the scales adopted to be reduced to a common system. 

 This seems to give sufficient latitude, but, nevertheless, at 

 the eleventh hour, no less than five dififerent papers are 

 presented on this vexed question of magnitude. Among 

 other papers forming the annexe is a short but interesting 

 note from the Astronomer Royal on the number of stars 

 found on each of the plates devoted to photographmg 

 the Polar Cap, with a comparison with the numbers 

 ■comprised in the Durchmusterung and the accurate 

 catalogues of the Astronoraische Gesellschaft. The totals 

 are as follows : — 



Number of stars measured on the plates ... ... 58,176 



Number of stars to the square degree ... ... 70*0 



Number of stars in Argelander's Durchmusterung 9979 



Ratio of photographed stars to Bonn D.M. ... 5'S3 



Number of stars in A. G.C. Catalogues .... ... 4966 



Ratio of photographed stars to A. G.C 117 



If the number of stars approximately increases as the 

 magnitude diminishes, the ratio here given would point 

 to the faintest stars on the plate being i '9 mag. fainter 

 than Argelander's faintest stars, or well covering the 

 eleventh magnitude, originally assigned as the limit to 

 which the catalogue should extend. 



Since writing the above, M. Loewy has published very 

 complete details showing the approximate times of 

 observation of the planet Eros at no less than forty-six 

 observatories where the work has been undertaken. The 

 energy displayed is of the most gratifying character, and 

 the tinal result will no doubt demand a degree of con- 

 fidence commensurate with the labour that has been 

 bestowed on the undertaking. The work is shown to be 

 one of gigantic magnitude, and M. Lccwy displays con- 

 siderable hopefulness in suggesting that two years may 

 see it completed. Several other papers, all devoted to 

 securing accuracy and homogeneity in tlie final reductions, 

 also appear in this brochure. We may especially call 

 attention to a paper by the Director of the Paris Observ- 

 atory on the degree of precision that the photographic 

 measures possess, and of the success that is likely to 

 attend the adoption of the scheme for driving the 

 equatorial at various rates depending on the amount of 

 geocentric motion of the planet itself. The additional 

 matter supplied by the Paris authorities is of a highly 

 interesting character to which we hope to do justice later, 

 when complete details from the various authorities are 

 published. 



THE COLORADO POTATO BEETLE. 

 "T^ HE official announcement by the Board of Agricul- 

 -*■ ture of the appearance of the Colorado potato 

 beetle swarming in a potato field at Tilbury is a very 

 serious matter, for we have no wish to see another insect 

 pest added to those with which our agriculturists already 

 have to contend. It is satisfactory to know that the 

 Board took instant measures to cause the destruction of 

 all the crops within the infested area ; and as the sur- 

 rounding neighbourhood has since been searched in 

 vain for any further traces of the insect, it is confidently 

 hoped that the measures taken for its timely extirpation 

 have proved successful. 



The beetle is about half an inch long, and slightly oval 

 in form. The wing-cases are longitudinally and alternately 

 striped with black and yellow, and the wings are red. 

 The grubs, which feed on a great number of other wild 

 and cultivated plants besides the potato, are orange or 

 reddish, with a row of black spots on each side. The 

 oval yellow eggs are laid in clusters. 



The insect was so destructive in North America some 

 years ago that great fears were entertained of its spread- 

 ing to Europe ; and at that time was passed the Destruc- 

 tive Insects Act, according to which every person meeting 

 with the insect is bound, under a penalty of 10/., at once 



NO. 1662, VOL. 64] 



to inform the police, who in their turn must notify the 

 local authorities, who must communicate by telegraph 

 with the Board of Agriculture. 



It niust be remembered that, if there is danger of an 

 injurious insect establishing itself in a -country, instant 

 action is as necessary as in the case of a threatened 

 epidemic. W. F. Kirby. 



PROF. BARON ADOLF ERIK 

 NORDENSKJOLD. 



VON 



\V/'HEN a man who has spent an earnest and useful 

 life reaches the mature age of threescore years 

 and ten, it must be a relief to those near and dear to 

 him when his last days are not spent in suffering. The 

 great Swedish explorer's end was- in this wise. "His 

 death," writes his nephew, Dr. Otto Nordenskjold, "was 

 absolutely sudden ; the same day he was working in his 

 laboratory, occupied with great plans in his mineralogical 

 and chemical work." 



Baron Adolf Erik von Nordenskjold was born at 

 Helsingfors, the capital of Finland, on November 18, 

 1832, the third in order of seven children. His father. 

 Nils Gustav Nordenskjold, descended from a scientific 

 family, and, himself an ardent naturalist, was chief of 

 the Mining Department of Finland. Nils Gustav was a 

 most distinguished mineralogist, and his work brought 

 him into communication with the most eminent mineralo- 

 gists and chemists of his tiine in France, Germany, and 

 Britain. He travelled as far as the Urals, and on many 

 of his journeys he was accompanied by his son, Adolf 

 Erik von Nordenskjold, who as a boy became an indus- 

 trious collector of minerals and insects. He acquired 

 great skill in collectmg minerals and in the use of the 

 blow-pipe, which his father handled with a masterly skill, 

 unknown to most of the chemists of the present day. 

 Thus, both by inheritance and by the influence of 

 environment, Nordenskjold had opportunities allotted 

 only to the few, but which were taken the greatest 

 possible advantage of. His early education was from 

 private tuition, after which he was sent to " gymnasium " 

 at Borgo, a connecting-link between school and university. 

 Here he distinguished himself, as the rector expressed it, 

 "only by absolute idleness." He was marked in his 

 certificate "unsatisfactory" in nearly the whole of the 

 subjects. His parents were judicious enough not to attach 

 any importance to this well-deserved mishap. His 

 private tutor was removed ; and with five silver roubles 

 Nordenskjold had to seek modest board and lodging, 

 and got full liberty to manage his studies in his own 

 way. "JSelf-respect," he says, " was thus awakened. I 

 became exceedingly industrious, and was soon one of 

 those then attending the gymnasium who obtained the 

 best reports." 



Nordenskjold entered the University of Helsingfors in 

 1849, devoting himself chiefly to the study of chemistry, 

 natural history, mathematics, physics, and, above all, of 

 mineralogy and geology. He took charge of the rich 

 mineral collection of Feugard, and made many excur- 

 sions. In 1853 he accompanied his father on a mineralo- 

 gical tour to Ural, when he planned an expedition to 

 Siberia, which the Crimean War prevented him from 

 carrying out. On his return he wrote, as his dissertation 

 for the degree of licentiate, a paper " On the Crystalline 

 Forms of Graphite and Chondrodite," which was dis- 

 cussed under the presidency of Prof. Arppe on Feb- 

 ruary 28, 1855. At this time he published "A Descrip- 

 tion of Minerals found in Finland," " The Mollusca of 

 Finland " with Dr. E. Nylander, and shorter papers 

 in the "Acta Societatis Scientiarum Fennia:." During 

 this time he was appointed Curator of the .Mathematico- 

 Physical Faculty and to a post at the Mining Office with 

 inconsiderable pay. Before he received his second 



