92 



NATURE 



[March 17, 192 1 



Calendar of Scientific Pioneers. 



Marph 17, 1771. Chester Moor Hall died. — An Essex 

 landowner and a lawyer, Hall in 1733 was the first to 

 construct an achromatic telescope. 



March 17, 1782. Daniel Bernoulli died. — Trained as 

 a mathematician by his brother Nicholas, Daniel 

 Bernoulli added greatly to the fame of the family. 

 Like Euler, his lifelong- friend, he received no fewer 

 than ten prizes from the Paris Academy of Sciences. 

 His best-known work was that on hydrodynamics. 



March 17, 1846. Friedrich Wilhelm Bessel died.— 



One of the greatest of astronomers, Bessel was 

 director of the Konigsberg Observatory, where he 

 erected the first of Fraunhofer's heliometers. Among 

 his most important labours were the reduction of 

 Bradley's observations, the determination of the 

 parallax of 61 Cygni, his ■ two catalogues of stars, 

 and in pure mathematics the invention of Bessel's 

 functions. 



March 17, 1853. Christian Doppler died.— Doppler 

 was a professor of mathematics at Prague. In 1842, 

 in a paper on the coloured light of double stars, he 

 enunciated the well-known principle which bears his 

 name, 



March 18, 1871. Augustus de Morgan died. — ^The 

 first professor of mathematics in University College, 

 London, de Morgan exercised a great influence by his 

 teaching and writings on mathematics and logic. He 

 was deeply versed in the history of mathematics. 



March 18, 1907. Pierre Eugene Marcellin Bertheiot 

 died. — Professor of organic chemistry in the College 

 de France and secretary to the Paris Academy of 

 Sciences, Bertheiot made im{X)rtant researches in 

 thermo-chemistry, explosives, and synthetic chemistry. 



March 20, 1727. Sir Isaac Newton died. — Uni- 

 versally recognised as the world's greatest mathe- 

 matical physicist, Newton was born on Christmas 

 Day, 1642. In 1669 he became Lucasian professor of 

 mathematics at Cambridge, in 1689 was elected 

 Member of Parliament for the University, and in 

 1699 was made Master of the Mint. From 1703 

 until his death he was president of the Royal Society. 

 His "Principia" was published in 1687. His grave 

 is in the nave of Westminster Abbey, while his 

 monument — the long inscription on which evoked a 

 protest from Johnson — stands close by. The statue 

 of Newton by Roubillac at Trinity College,' Cam- 

 bridge, bears the words : " Qui genus humanum 

 ingenio superavit." 



March 20, 1878. Julius Robert von Mayer died. — 



One of the founders of the science of thermodynamics, 

 Mayer in 1841 settled at Heilbron as a physician, and 

 his memoir on the mechanical theory of heat was 

 published the following year, 



March 21, 1762. Nicolas Louis de Lacaille died. — 



Lacaille was the first to measure an arc of meridian 

 in South Africa. He published three catalogues of 

 stars, the second of which was based on his work at 

 the Cape of Good Hope in 1750-54. 



March 22, 1772. John Canton died. — A private 

 schoolmaster in Spitalfields, Canton was a keen ex- 

 perimentalist. He made improvements in electricity 

 and demonstrated the compressibility of water. 



March 23, 1899. Gustav Heinrich Wiedemann 

 died. — ^The successor In 1877 of Poggendorf as editor 

 of the Annalen der Physik und Chemie, Wiedemann 

 was known for his accurate physical determinations 

 and for his monumental work entitled " Die Lehre 

 von der Elektricltat. " E. C. S. 



NO. 2681, VOL. 107] 



Societies and Academies. 



London. 

 Linnean Society, February 17. — Dr. A. Smith Wood- 

 ward, president, in the chair, — Prof, G. B. De Toni -. 

 A contribution to the teratology of the genus Datura, 

 L. A hitherto unreported malformation of the flower 

 of D. stramonium. A plant grown in the Botanical^ 

 Garden at Modena produced flowers of two kinds ; 

 normal flowers appeared on the lower part of the 

 plant and produced perfect capsules, but flowers pro- 

 duced in the upper part of the plant later in the 

 year were barren. — Capt. J. Ramsbottom : The col- 

 lection of plants made by various members of H.M. 

 Salonika Forces. A plant-collecting competition 

 amongst warrant officers, non-commissioned officers, 

 and men was held. The result of the competition 

 was satisfactory, as it also had the effect of cen- 

 tralising effort and attracting a considerable number 

 of other collectors. The district in which the prin- 

 cipal collectors were stationed was indicated on a 

 map. — Dr. G. C. Druce : A short account of botanical 

 work in the Shetlands, A Plantago from the north 

 of Balta Sound, which may be compared to P. w,ari- 

 tima, var. minor, Hook., renamed by Boswell Syme 

 var. hirsuta, was discussed. Cerastium. subtetran- 

 drum., Murb., Potamogeton suecicus, C. Richt., P. 

 rutilus, Wolfg., Rhinanthus horealis, Druce, and Poa 

 irrigata, Lindm., are described as new to the flora. 

 Nitella nidifica, Ag., found In the Loch of Stenness, 

 and Chara canescens, H. and J. Groves, are new to 

 the Scottish flora. 



Geological Society, February 18. — Mr. R. D. Oldham, 

 president, in the chair. — R. D. Oldham : Presidential 

 address : Know your faults. The address was devoted 

 to a consideration of the dangers of a loose use of 

 words. The first Instance taken was that of the 

 common classification of faults as normal and 

 reversed. It became generally accepted that normal 

 faults in the technical sense were normal in the 

 dictionary sense, though this is not always in accord 

 with experience. Reversed faults were then con- 

 sidered, A consideration of possible modes of forma- 

 tion led to the conclusion that the words "upthrow" 

 and "downthrow" indicate no more than the relative 

 displacement of the two sides of the fault. Passing 

 on to the word " overthrust," the president pointed 

 out that it implied the two concepts that the upper 

 block was thrust over the lower, and that Its dis- 

 placement was due to the action of some external 

 fault. With regard to the former, there is no means 

 of deciding, from observations within the area of the 

 overthrust, whether the upper or the lower block had 

 been displaced or had remained stationary. With re- 

 gard to the latter. It was deduced that the movements 

 must have taken place piecemeal, and that the cause 

 must have been generated within the area affected. 

 As it is difficult to conceive of any such action taking 

 place in the dead matter of the upper block, the con- 

 clusion Is suggested that the originating cause lay in 

 the lower, and the "overthrust" becomes an "under- 

 crawl." 



February 23. — Mr. R. D. Oldham, president, In 

 the chair.— Prof. W. J. SoUas : Saccammina Carteri, 

 Brady, and the minute structure of the Foraminlferal 

 test. An investigation was made into the composi- 

 tion and structure of the test In the vitreous and 

 porcellanous Foramlnifera. In both groups the sub- 

 stance of the test consists wholly of calcite. The dis- 

 tinctive difference lies In the granular and felted 

 structure which characterises the porcellana. Per- 

 forate Foramlnifera and porcellanous forms occurring 

 In association with Saccammina retain the original 



