638 



NATURE 



[July 14, 192 1 



Calendar of Scientific Pioneers. 



July 14, 1827. Augustin Jean Fresnel died. — An 



officer in the Corps des Fonts et Chaussees, Fresnel 

 during the last twelve years of his life devoted him- 

 self to experimental and mathematical researches in 

 optics. Like Young, he did much to establish the 

 undulatory theory of light. 



July 14, 1879. Sir Thomas Maclear died. — Trained 

 as a doctor, through Admiral Smyth Maclear took 

 up astronomy, and from 1833 to 1870 was Royal 

 Astronomer at the Cape of Good Hope. Among other 

 work was his extension of Lacaille's arc of meridian. 



July 14, 1907. Sir William Henry Perkin died. — 

 The discoverer in 1856 of the first of the aniline dyes, 

 aniline purple or mauve, Perkin established a factory 

 for its manufacture, and thus became the founder of 

 the great coal-tar colour industry. His success, 

 ■especially with the manufacture of alizarin, enabled 

 him in 1874 to retire, after which he made important 

 investigations of questions of chemical constitution. 

 He was knighted at the jubilee of his great discovery. 



July 17, 1878. Thomas Oldham died.— After hold- 

 ing the chair of geology at Trinity College, Dublin, 

 Oldham in 1850 was appointed by the East India 

 Company the first Superintendent of the Geological 

 Survey of India. 



July 17, 1899. Charles Gravesai died. — The succes- 

 sor of McCullagh in the chair of mathematics in 

 Trinity College, Dublin, Graves contributed mathe- 

 matical memoirs to Cr die's Journal, and served as 

 president of the Royal Irish Academy. 



July 17, 1912. Jules Henri Poinoare died. — Born in 

 "Nancy in 1854, Poincar6 in 1908 was elected presi- 

 dent of the Academy of Sciences of Paris, by which 

 time he had written 1300 books and memoirs relating 

 to pure mathematics, mathematical physics, astro- 

 nomy, and philosophy. 



July 18, 1650. Christoph Scheiner died.— A member 

 of the Society of Jesus and an opponent of the views 

 of Copernicus and Galileo, Scheiner was one of the 

 •earliest observers of sun-spots. He taught at Frei- 

 l»urg (Baden), Rome, and Ingolstadt, and was rector 

 ■of a Jesuit college in Silesia. 



July 18, 1819. Barthelemy Faujas de Saint-Fond 

 "died. — Attracted to natural historv bv Buffon, Faujas 

 •de Saint-Fond became professor of geology in the 

 Jardin des Plantes. He travelled much, wrote a 

 ■valuable work on extinct volcanoes, and was the first 

 scientific writer to direct attention to the basalt pillars 

 of the Isle of StafTa. 



July 19, 1814. Matthew Flinders died. — Known 

 for his important survey of the Australian coast, 

 Flinders mad* observations on the compass, and to 

 liim we owe the "Flinders bar" for neutralising a 

 •ship's magnetism. 



July 19, 1838. Pierre Louis Dulong died. — Dulong 

 ■was director of studies at the Ecole Polytechnique, 

 and in 1832 became one of the secretaries of the 

 Paris Academy of Sciences. In 18 19 with Petit he 

 •enunciated the law connecting the atomic weight of 

 a substance with its specific heat. 



July 19, 1882. Francis Maitland Balfour died. — 

 Xil'ed at the age of thirty-one when climbing Mont 

 Blanc, Balfour had just been appointed to a newly 

 •created chair of animal morphology at Cambridge. 

 His "Comparative Embryology " appeared In 1880-81. 



July 20, 1819. John Playfair died.— An Edinburgh 

 professor, Playfair's principal contribution to science 

 was his "Illustrations of the Huttonian Theorv of the 

 Earth." 



July 20, 1866. Georg Friedrich Bernhard Riemann 

 'died. — Successor of Dirichlet in the chair of mathe- 

 matics at Gottingen, Riemann was one of the most 

 profound mathematicians of his time. E. C. S. 



NO. 2698. VOL. 107] 



Societies and Academies. 



London. 

 Geological Society, June 22.— Mr. R. D. Oldham, 

 president, in the chair. — Dr. C. T. Trechmann and 

 L. F. Spath : The Jurassic of New Zealand. The 

 Jurassic beds of New 2^aland comprise an important 

 set of sediments, probably 10,000 ft. in thickness, 

 exposed at certain points extending over the length 

 of the North and South Islands. They follow the 

 Trias with apparently perfect conformity. The ^iflfini- 

 ties of the fossils from the Lower Lias to the Upper 

 Jurassic formations are with those occurring in the 

 Jurassic of the Argentine Andes, Western Australia, 

 the Sula Islands, the Spiti Shales of the Himalayas, 

 and the Jurassic deposits of Kutch. Descriiitions of 

 New Zealand ammonites from the British Museum 

 collections, notably a small fauna of typically Medi- 

 terranean aspect, which is referred to the Middle Lias, 

 were given. — F. Dixey : The norite of Sierra 

 Leone. The norite of Sierra Leone constitutes a com- 

 plex of which the oldest and most important member 

 is an olivine-norite. The complex forms the moun- 

 tainous mass which, with a narrow coastal plane of 

 Pleistocene sediments, makes up the Sierra Leone 

 peninsula. The norite was intruded in the form of 

 a huge stock ; it has no marginal or basic modifica- 

 tions, while its junction with older rocks is obscured by 

 the Pleistocene sediments. The complex is probably 

 somewhat later than Pre-Cambrian in age. The maiii 

 intrusion of norite was invaded in succession by minor 

 intrusions of vounger norites, noritc-pegmatite, beer- 

 bachite, norite-aplite, and dolerite. Features of the 

 older norite are welWeveloped fiow-banding, a series 

 of binary and ternary intergrowths of the common 

 minerals, and metamorphism due to the minor in- 

 trusions. Iron-ores occur in the norite as small 

 masses, narrow schlieren, and disseminated grains; 

 they are highly titaniferous. Sulphides and other 

 economic minerals are rare or absent, 



Edinburgh. 

 Royal Society, Julv 4. — Prof. F. O. Bower, president, 

 in the chair. — C. T. R. Wilson : Recent work on 

 lightning and thunderstorms. A thundercloud may 

 be regarded as a great electrical machine, and 

 suggests such questions as the electromotive force 

 developed by the machine, the current which passes 

 through it, and the external distribution of the 

 current. It is at present mainly from a study of the 

 electric force at the ground during thunderstorms that 

 we obtain information on these points. Records were 

 shown of the changes in the electric field due to 

 thunderstorms at a distance, and of the sudden 

 changes produced by lightning discharges. From the 

 results of automatic records of this kind it is con- 

 cluded that in an average lightning flash a quantity 

 of electricity amounting to about 20 coulombs 

 passes, and that the potential difference required to 

 cause the discharges is of the order of one thousand 

 million volts. In addition to lightning discharges 

 there may be considerable continuous currents main- 

 tained by the thundercloud. The electrical energy 

 going to waste in a thunderstorm may amount to a 

 million horse-power. A large part of the current main- 

 tained by the thundercloud may pass through the 

 cloud from the ground to the conducting upper atmo- 

 sphere, or from the upper atmosphere to the ground, 

 and produce effects which are of importance in con- 

 nection with the atmospheric electricity of fine 

 weather, and p)ossibly with terrestrial magnetism. — 

 Prof. H. Briggs : The adsorption of gas under pres- 

 sure. The author describes a series of experiments 



