156 



NATURE 



{June 2 1, 1877 



therefore, when the Greek seaman or agriculturist was often 

 spending the nights out of doors, the late time at which this 

 brilliant star would set must have been quite unmistakable, and 

 Ulysses is naturally described as keeping his eye fixed on it while 

 sailing eastwards, as carefully as he kept the Bear on his left. 

 Again in the " Fasti " of Ovid, i. 654, ii. 76, we are told that 

 Lyra, or Ve^, was last visible when setting in the evening, about 

 February I. " Ubi est hodie, quae Lyra fulsit heri ? " Em- 

 ploying again the method of calculation indicated above, we find 

 on that day at Rome the sun would set about 5.10 r, M., and 

 Lyra about 5.44. As the days at that time of the year are 

 rapidly lengthening, while the star would set earlier every day, 

 it is obvious that the date assigned for the last appear- 

 ance of the latter is nearly exact. Ovid's references to 

 Arcturus are not at first sight so satisfactory. May 26th 

 and June 6th (" Fasti v. 733, vi. 235) are both assigned as 

 the first days on which he is visible, probably by a mistaken 

 reference to two different modes of calculating the time of a 

 star's rising. On May 26 the star would rise at 4.25 a.m., on 

 June 6 at 3.43 a.m. The sun on the former day rises at Rome 

 about 4.35, and on the latter at 4.30 a.m. If we consider Ovid 

 to have consulted two different authorities, one of which gave 

 the true and the other the visible heliacal rising of the star, no 

 reasonable exception can be taken to the value of his state- 

 ments, lie makes, however, a remark about Capella which 

 seems really erroneous. Me says (" Fasti " v. 113) that she rises 

 on May 1st, i.e , is then first visible in the morning. But at the 

 time when Ovid lived she would, according to the mode of 

 compulation used in the previous examples, have risen about 

 3.0 A.M., while the sun would not have risen until after 5.0. We 

 have a similar apparent mistake in Pliny and Columella, nearly 

 contemporaries, who fix Arcturus' rising for the 23rd or 21st of 

 February. On that day the sun would set at Rome about 5.35 

 r.M., whereas the star would not pass the horizon before 6.30 

 P.M. They seem to have copied from Hesiod without any thought. 

 The late Mr. F. Baily, in his edition of "Ancient Star Catalogues," 

 published in vol. xiii. of the Memoirs of the Royal Astronomical 

 Society, does not seem to have actually compared the positions 

 there given to any of the principal stats with those which in the 

 present day we must suppose them to have then occupied. As, 

 however, the present rate of change in the obliquity of the 

 ecliptic would have made it in the time of Eratosthenes (230 

 li.c. ) about 23° 43', whereas that astronomer fixes it roughly at 

 23° 51', it is to be hoped that, making allowance for inaccuracies 

 in the .MSS., such a process of verilication may be attempted 

 with some prospect of success ; and possibly some explanation 

 found of Ptolemy's idea that in his time (a. D. 140) the amount 

 of 3.nmi2\ precession was only 36". — Mr. J. W. L. Glaisher com- 

 municated to the society a ten-figure table of the values of f' and 

 t''-, with their logarithms from ,< = i to jr = 500 at unit inter- 

 vals. The table was intended to accompany Prof. F. \V. New- 

 man's table of e-", and will appear with it in the Traiisaclions 

 of the Society. 



Paris 

 Academy of Sciences, June it. — M. Peligot in the chair. — 

 The following papers were read : — On the densities of v.ipour ; 

 reply to M. II. Sainte-Claire Deville, by M. Wurtz. — On the 

 atomic notation ; reply to M. Berthelot, by M. Wurtz. — Second 

 note on the Nouvelle Navigaliou of M. Villarceau, apropos of 

 the interior sea of the Algerian .Sahara, by M. Naudin. He 

 urges that the result would very probably be an immense pesti- 

 lential focus. The slope would be slight, and the depth of water 

 in the border of the lake small. A large portion of land would 

 thus be alternately covered with water in the rainy season, 

 and left dry in the summer ; and with the mixture ol salt and 

 fresh water, bright solar light, and tropical heat during two-thirds 

 of the year, there would be active generation of organisms, the 

 putrefaction of which must corrupt the air all round. — Theory for 

 finding the number of co-variants and contra-variants of order and 

 degree, given, linearly independent of any system ol simultaneous 

 forms containing any number of variables, by Mr. Sylvester. — On 

 the rotatory polarisation of quartz, by MM. Soret and Sarasin. 

 They have extended their researches to the ultra-violet radia- 

 tions, using the light had from induction sparks between cad- 

 mium points and applying the spectroscope with fluorescent eye- 

 piece. — Observations on the ovigerous tubes of the Phylloxera, 

 by M. Boiteau. — Results obtained at Cognac since 1875, ^"i 

 the use of alkaline sulpho-carbonates, by M. Monillcfert. — 

 On the use of sulpho-carbonates, by M. De Georges— On a new 

 electric lamp with oblique circular rheophores, by M. Regnier. 

 He was led to this arrangement from having observed that with 



rheophores meeting angularly the most of the light was emitted 

 at the summit of the angle. The occultations — hitherto inse- 

 parable from carbon discs — are suppressed. Each rheophore has 

 its own clockwork movement, and the motors, pivoted, can 

 oscillate with their respective rheophores. One is manccuvred 

 by the operator, who puts the carbons in position ; the 

 other, commanded by a solenoid in the circuit, oscillates 

 automatically, bringing the carbons in contact, or sepa- 

 rating or approximating them at the proper time. — M. Cance 

 presented a new system of electro-magnets with multiple cores, 

 in which M. Camacho's tubular cores are replaced by small soft 

 iron rods juxtaposed, and enveloping, two by two, the different 

 layers of spiral ; this gives certain advantages. — M. Trouve pre- 

 sented an improved sound for wounds caused by fire-arms. — 

 On the infinitely small displacement of a dihedron of invariable 

 size, by M. Mannheim. — Historical remarks on the theory of 

 motion of one or several bodies, of constant or variable 

 forms, in an incompressible fluid (continued), by M. Bjerknes. — 

 On certain functions, similar to circular functions, by M. 

 Appell. — Comparative study of observations by day and by 

 night ; second note, by M. Perrier. He finds that azi- 

 muthal observations by night have a degree of precision 

 at least equal, if not superior to that of observations by day, 

 and thinks they should forthwith be introduced into the practice 

 of geodesy. — On the determination of the zenith of a ship or 

 point observed at sea by means of straight lines of height ; in- 

 sufficiency of the zenith or place of the ship called ///<• most pro- 

 bable ; determmation of a point nearest the true zenith, by M. 

 jSertot. — Researches on the use of magneto-electric machines 

 with continuous currents, by M. Gramme. With baths 

 coupled in tension, M. Wohlhill, of Hamburg, got a deposit 

 corresponding to 43 kilogr. of silver per hour, whde expending 

 15-horse power on the machine. M. Gramme describes several 

 experiments by himself of this nature. — Influence of a mechanical 

 action on the production of various hydrates in supersaturated 

 saline solutions, by M. Gernez. — On the new general method of 

 synthesis of hydrocarbides, acetones, &c. , by MVI. Friedel and 

 Crafts. — Researches on normal propylene, by MM. Reboult and 

 Bourgoin. — Composition of a substance formed on an iron rod 

 altered by a Siemens gas furnace, by M. TerreiL Under the 

 simultaneous action of the oxidising and reducing gases of the 

 furnace, the iron was transformed almost wholly into anhydrous 

 protoxide of iron. M. Daubree made some remarks^on this. — ■ 

 On the asparagine of amygdalene ; hypothesis on its physio- 

 logical role by M. Portes. 



CONTENTS Page 



The Organisation ok Natural History Museums. By Prof. W. 



BovdDawkins, F.R.S 137 



Cauboniferous Flora of Central France. By Prof. W. C. 



Williamson, F.R.S 138 



Our Book shelf ; — 



*' Annies do Observatorio do Infante D. Luiz. Magnetismo 



Terrestre."— John Allan Broun, F.R.S. .^ 139 



Malet's " Incidents in the Biography of Dust " 139 



Lubavin's "Chemical Physics" 140 



Calderon's " Enumeracion de los Vertebrados Fdsiles de Espaiia" 140 

 Letters to the EniTOR :— 



Museum Reform — F. W. Rudler ; William Gee ; Arthur 



Wm. Waters 140 



The Antiquity of Man.-Dr. James Geikie, F.R.S. ; Sydney B. 



J. .Skertchlv 141 



Nicephore Niepce. — H. Baden Pritchard 142 



Japanese Mirrors.— R. D. Darbishire 142 



Colour-Sense in Birds.— Paul Henry Stokoe 143 



Our Astronomical Column : — 



Variable Stars - 143 



Minor Planets and Comets of Short Period 143 



Meteoric Fire-Balls in America 143 



The Transit of Venus, 1882 144 



The Land of Hissar and Kolab . . 144 



How to Draw a Straight Line, IV. By A. B. Kempe, B.A. (WjM 



Itliistratitms) 145 



Biological Notes : — 



The Tichorhine Rhinoceros 146 



Oscar Hertwig on the Phenomena of Fertilisation 147 



Individual Variations in Animals 147 



A New Cheet.-ih 147 



North American I.epidoptera 147 



A New Shell 147 



Geological Notes:— 



Rare Minerals in the North of Scotland 147 



Tertiary Leaf-beds of Colorado 148 



Influence of Anchor-Ice upon Fishing-Grounds T48 



Origin of the Trees and Shrubs in the South of France .... 148 



U S. National Academy of Sciences 148 



Notes 151 



University and Educational Intelligence 153 



SciBNTipic SER1AI.S 154 



SOCIBTIKS AMD ACABKMIBS 154 



