May 8, 1879] 



NATURE 



41 



The Carpi prize of the Reale Academic de' Lincei for iSSo 

 (value 500 lire) will be awarded to the author of the best mono- 

 graph On tht Organs and Vital Functions of Plants. Memoirs 

 to be sent in before December 31, 1880. The conditions are the 

 ^iame as in 1878. 



A NEW nautical instrument, called a tiavisphert, has been 

 iirought before the French Academy by M. De Magnac. It is 

 meant to indicate, without calculation and promptly, the names 

 of the stars above the horizon at a given moment (with altitude 

 and azimuth), the angle of route for going from one point to 

 another by the arc of a great circle, and the distance between 

 these points (approximately). Spherical triangles may also be 

 solved with it. The instrument consists of two parts, the one a 

 celestial sphere with stars marked on it, resting on a spherical 

 zone, to which all possible positions maybe given; the other 

 comprises the system of the horizon, the meridian, and the ver- 

 ucal, represented by a circle, a semicircle, and a quarter of a 

 circle in metal. With this system of arcs one can trace arcs of a 

 great circle on the sphere, and measure their lengths, also measure 

 the angles formed by two great circles. The second part of 

 the apparatus is called a metrosphtre. The experiments with the 

 itavisphere, made on board the Atlantic steamship Washington 

 appear to have been highly encouraging. 



In the spectral examination of the new earth recently extracted 

 from erbi«e by M. Nilson, M. Thalen found the following lines 

 :>roper to the spectrum of that substance. (Comptes Rendus, 

 March 24.) 



Intensity 



• 3 • 



Remarks. 

 Broad and nebulous. 



Nebulous. 

 Nebulous. 



Very fine and clear. 



Strong. 



Fine. 



Colour of rays. Wave-length. 

 (-6078-5 



1 6072-5 ... 3 



Orange -(6054-0 ... 5 



I 6035-0 ... 2 



1 6019-0 ... 4 



(^5736-0 ... 6 



5729-0 ... 6 



57190 .., 4 



VI, "'°'^ •• "^ 



lellow -{5700-0 ... 4 



56860 ... 4 



567i'o ... 4 



5657-5 ••• 4 

 15526-0 ... 2 

 /• 5089-0 ... 6 



15084-5 - 5 



Gi'een i 5082-3 ... 4 



5081-0 ... 3 



15030-0 ... 3 



( 4742-5 ■•■ 3 



Blue ) 4739-0 ... 4 



) 4736 s - 5 



(4733-0 - 5 



4404-0 ••■ „ 



4373'o •• „ 



Indigo -' 4323-0 ... „ 



i 4319-0 



! 4313-0 ... „ 

 -4245-5 - „ 



iiesides these lines, several others were observed which belong 

 to the spectrum of ytterbium, and which have already been indi- 

 cted by M. Iloglund in the spectrum of erbium. For the new 

 .ement M. Nilson proposes the name scandium, to denote its 

 , iculiarly Scandinavian origin. 



The International Congress of Americanists has issued its 

 circular of invitations to a third session, to be held at Brussels 

 from September 23 to 26, under the patronage of the King of 

 liclgium and the presidency of the Count of Flanders. The 

 ity of Brussels will t.ike charge of the Congress, and see to the 

 ; roper accommodation and convenience of the members. The 

 "bject of this organisation is the development of a knowledge of 

 the early history of discovery and settlement in the Americas, as 

 also all such facts in their prehistory as can be gathered by an 



inspection of the remaining monuments. The volumes of 

 Proceedings contain a great deal of interesting and important 

 matter, although the Society is rather open to the charge of 

 credulity in accepting, apparently without question, many state- 

 ments repudiated by American archceologists. This, however, 

 would be remedied by a larger representation from North 

 America ; and it is much to be hoped that some of our more 

 accomplished American historians and ethnologists may take 

 part in the proceedings of the coming season. 



It is known that the first aerial voyage was made by Pilatre 

 de Rozier, in company with the Marquis d'Arlandes, in a Mont- 

 golfiere, or heated air balloon, on November 21, 1783. Pilatre 

 was also the first victim of aerostation ; he perished along with 

 his companion Romain by the fall of a balloon at Boulogne. 

 Three pieces which belonged to the unfortunate physicist are 

 exhibited in the museum there : his speaking-trumpet, mercury 

 barometer, and thermometer. Recently some other precious 

 relics from the same origin have been found in a drawer in the 

 museum. They are chiefly a plaster medallion of Pilatre, a part 

 of the painted cloth which covered the gallery of the balloon, 

 and the flagstaff. Engravings of the.se and the former relics of 

 Pilatre are given in a recent number of La Nature (April 26), 

 which also reproduces a detailed account of the fatal ascent. 



The extent of variability in composition of atmospheric air is 

 a question treated by Herr von Jolly in a recent communication 

 to the Bavarian Academy. By two methods of measurement, 

 the one eudiometric, the other based on weighing, he observed 

 variations that are not quite inconsiderable. The air samples of 

 the year 1877 (got 2 km. out of town) showed differences in the 

 oxygen from 21-01 down to 20-53 ps"- cent., and in 1875 'o 

 1S76 the highest and lowest proportions (obtained by weighing) 

 were 20-96 and 20-47 P^"^ cent, respectively. The variations ia 

 the two years were thus nearly the same. The largest amount 

 of oxygen occurred in both years when the polar current was 

 prevalent ; the smallest with the equatorial current or fohn. It 

 is not affirmed, however, that whenever the wind is north or 

 north-east, there is necessarily more oxygen, and when it is south 

 and south-west, less ; or that differences of 0-5 per cent, occur 

 with every reversal of the wind. The more rapidly the direc- 

 tions of wind alternate, there is more mixture of air masses ; and 

 therefore there is never so much oxygen as with continuous polar 

 current, or so little as with continuous equatorial. Whether 

 from year to year the mean proportion of oxygen is the same, or 

 whether, as is more probable (the duration of polar and equa- 

 torial currents varying from year to year), there are slight diff-er- 

 ences in this average, can only be determined by further obser- 

 vations. 



During the conjunction of the planets Mercury and Venus, 

 on September 30 last year, measurements of their relative power 

 of light-reflection were made at Strasburg Observatory (we 

 learn from Astr. Nachr.) by Herr Schnur. The half-objective 

 of the telescope which showed Venus was gradually shaded by 

 measurable quantities till equal surface-portions of Venus ap- 

 peared of the same brightness as those of Mercury through the 

 unshaded part. The measurements on September 30 gave for 

 relative light intensity the value 6-75, and on October 2 the value 

 5-36 ; the latter figure is considered the more reliable, and may 

 be accepted for the relative brightness of Mercury and Venus. 

 Herr Zollner, by a quite different method, got 5-5. 



Applications for the intended Exhibition of Applied Science 

 in Paris may be sent to M. NicoUe, director, 10, me de Lancry, 

 Paris. The presidency of the Patronage Committee has beem 

 accepted by M. Jules Simon. More than 200 English firms 

 have already sent in their adhesion, and more than 300 German 

 firms wish to protest against the abstention imposed by their 

 ov/n Government in 1878. A large number of these belong to 



