286 



NATURE 



[November 7, 1912 



Kam-Yei formerly constituted a portion of the Siamese 

 mainland. 



In a paper on the origin of asymmetry in Cetacea 

 published in vol. xli. (pp. 45-54) of the Anatomischer 

 Anzeiger, Prof. G. Steinmann argues that the hori- 

 zontal tail-fin of that group has been produced by 

 torsion from the perpendicular type characteristic of 

 the Mesozoic saurians. As the author believes ceta- 

 ceans to be a convergent group derived from three of 

 the Mesozoic marine reptilian orders (Ichthyosauria, 

 Plesiosauria, and Thalattosauria), it is, to say the least, 

 not a little curious that a similar torsion of the tail-fin 

 should have occurred in each group. The same author 

 has also sent us a copy of a pamphlet, by himself, 

 published by Engelmann, of Leipzic, and entitled 

 ■'Die Abstammungslehre, was sie bieten kann und 

 was sie bieten." 



The interesting and rare fresh-water alga Phaeotham- 

 iiion coiifervicoluin has recently been found near Edin- 

 burgh by F. L. M'Keever, who describes (Trans. Bot. 

 Soc. Edinburgh, vol. xxiv) the first recorded appear- 

 ance of this plant in Great Britain. The genus 

 Phaeothamnion has by the majority of recent sys- 

 tematists been placed at the base of the brown algae, 

 and may be regarded as one of the intermediate forms 

 in the ascending scale of brown organisms arising 

 from the Flagellata with brown chroniatophores 

 (Chrysomonads), and giving rise to the true brown 

 algse (PheBopliyceae), hence it is a type of special 

 interest from the phylogenetic point of view. Hitherto 

 this genus has been found only in Sweden, Germany, 

 Austria, and Italy. As the alga disappeared from 

 Mr. M'Keever's cultures before its zoospores could be 

 carefully studied, it is to be hoped that the plant 

 will be found again, and further investigations made 

 in order to determine its systematic position and 

 afiinities with greater certainty. 



P1.0F. W. E. Ford has edited the thirteenth edition 

 of "Dana's Manual of Mineralogy " (New York : Wiley 

 and Sons, 1912, price 8s. 6d. net), which continues 

 to be one of our best elementary text-books. The 

 photographic illustrations of actual specimens, printed 

 as separate plates, are distinctly helpful. As is usual 

 in the smaller works on mineralogy, crystallographic 

 considerations remain somewhat loosely stated. The 

 problem of isomorphism outside the cubic system is 

 not touched on in the three pages devoted to the 

 subject, and the statement on p. 11 that "in general 

 the ratio of the intercepts of a crystal face upon the 

 crystallographic axes can be expressed by whole num- 

 bers or definite fractions" is surely, in this abbreviated 

 form, misleading. Useful tables for the determina- 

 tion of minerals occupy nearly seventy pages. 



The Deutsche Seewarte has added another lustrum 

 (1906-10) to the valuable results of the meteorological 

 observations made at thi stations of the second order 

 under its control. The lustra previously dealt, with 

 cover the thirty years 1876-1905, and some of the 

 former have already been combined into longer periods, 

 e.g. in 1904 the results included the twenty-five years 

 1876-1900. The observations are made at 8h. a.m., 

 2h. and 8h. p.m., local time, and excepting at two 

 NO. 2245, VOL. 90] 



stations, where the English-pattern (Stevenson) screen 

 is used, the thermometers are installed outside suit- 

 able windows. The results are calculated for months, 

 seasons, and the year. 



.\ LENGTHY article (in Japanese) on observations of 

 air currents appears in the Journal of the Meteoro- 

 logical Society of Japan (xxxi.. No. 7, 1912). The 

 author, Mr. Sato Junichi, describes some experiments 

 which he carried out in January and February last on 

 the summit of Mount Tsukuba (2925 ft.), both with 

 small liydrogen balloons, known as " pilots," and with 

 pyrotechnic balloons. The latter, devised by himself, 

 are balloon-like firework pendants, which are released 

 at various heights, determinable from the nature and 

 quantity of explosives used. It is claimed that 

 whereas "pilots," being relea.sed at ground-level, are 

 at the mercy of surface winds from the start, the 

 fiiework balloons are carried through the lower strata 

 and begin their journey several hundred metres high. 

 For the observation of these balloons the author uses 

 a special form of theodolite, also designed by himself, 

 provided with a sighting attachment and a plummet, 

 and costing only a few pence. In the experiments 

 referred to, when comparative observations were made 

 with both types of balloon, air currents in the opposite 

 direction to those at ground-level were found at heights 

 of from two to five hundred metres. Details are given 

 of numerous observations, the information obtained 

 embracing speed and direction of air currents, the 

 location of upward and downward eddies in the atmo- 

 sphere, height of surface currents, &c. The meteoro- 

 logical conditions, nature of clouds, force and direction 

 of the wind prevailing on each occasion are also 

 given. 



In recording observations of periodic phenomena, it 

 is very usual to make a certain number of groups of 

 regular observations and to take the arithmetical 

 mean of each group. In a note on the application of 

 the method of harmonic analysis (Journal of the 

 Meteorological Society of Japan, xxxi., 5), Mr. V. 

 Tsuiji shows that when the results are used for the 

 purposes of harmonic analysis the coefficients thus 

 obtained are too small, and formulas and tables are 

 given for the necessary corrections. 



Under the title " Surfaces of Revolution of Minimum 

 Resistance," Dr. E. J. Miles, writing in the Bu'letin 

 of the American Mathematical Society, discusses the 

 form of an airship or other figure of revolution which 

 experiences the least resistance in its motion through 

 a resisting medium. The assumption made is that 

 the pressure on any surface element is a function of 

 the inclination of that element to the direction of 

 motion, and is unaffected by the currents set up by 

 the remaining portions of the surface, and in this 

 respect the problem differs essentially from that pre- 

 sented by an airship or body moving through a 

 material fluid medium. The problem is, however, a 

 classical application of the calculus of variations dating 

 back to the time of Newton. 



A SERIES of articles on the origin of the 

 earth's magnetic field have appeared in Terrestrial 

 Magnetism during the last two years from the pen 



