April 13, 1905] 



NA TURE 



569 



A BOOKLET on " Piittern Making," by Mr. J. E. Danger- 

 field, has been added by Messrs. Dawbarn and Ward, 

 Ltd., to their " Home Workers' Series of Practical Hand- 

 books." 



A NEW edition of Mr. W. Woods Smyth's " Divine Dual 

 Government " has been published by Messrs. Horace 

 Marshall and Son. The present issue has been revised 

 and illustrated with new matter, some of which has already 

 appeared in earlier books, now out of print, by the same 

 author. 



Messrs. Longm.vns, Green and Co. have published a 

 new edition of "Telegraphy," by Sir W. H. Preece, 

 K.C.B., F.R.S., and Sir J. Sivewright, K.C.M.G. The 

 book has been revised and enlarged, and now includes 

 descriptions of recent devices used in telegraphy, in re- 

 lation to fast-speed recorders, to automatic and translating 

 apparatus for submarine circuits, to Murray's improve- 

 ments in the Wheatstone automatic apparatus, and to the 

 new telegraph switching system. A chapter on wireless 

 telegraphy considered theoretically and in its most recent 

 application has been added. 



Mr. Henry Frowde has sent us two pages of the " New 

 English Dictionary on Historical Principles," edited by 

 Dr. J. A. H. Murray, to show how the word refraction 

 and its congeners are defined and traced. The number 

 of references to uses of these words is astonishing ; and 

 a vast amount of research must have been necessary to 

 bring so much material together. We extract a few early 

 references of historical interest : — Refracting, causing re- 

 fraction, refractive; 1704, Newton, "Optics" (1721), 

 4 def. iv., " the perpendicular to the reflecting or refracting 

 surface at the point of incidence "; 1764, Hornsby, in P/ii7. 

 Trans., liv., 145, "an excellent refracting telescope of 

 12 feet focus." Refraction; 1603, Holland, "Plutarch's 

 Mor.," 1295, " the rainbow is . . . distinguished by sundry 

 colours, by the refractior if our eie-sight against a cloud " ; 

 1646, Sir T. Browne, " Pseud. Ep.," 347, " the colours are 

 made by refraction of light, and the shadows that limit 

 that light"; Asiron. : 1603, Heydon, " Jud. Astrol.," 137, 

 " there lieth a deceipt or fallacie in the refraction of beams, 

 whi-rh cheifiy happeneth about the horizon, where the aire 

 is alwaies thickest"; 1669, Sturmy, Mariner's Mag., ii., 

 irS, "the refraction of the sun, moon and stars, causeth 

 them to appear higher above the horizon than they are." 

 Refractive; 1673, Flamsteed, in Rigaud's " Corr. Sci. 

 Men " (1841), ii., 168, " the refractive air reaches some 

 height above our heads"; a i6gi, Boyle, "Hist. Air" 

 (1692), igo, " the air . . . was filled with vapours and 

 exhalations, that made it much more refractive than 

 formerly." 



OUR ASTRONOMICAL COLUMN. 

 Comet 1905 a (Giacobini). — A further extract from Dr. 

 Stromgren's daily ephemeris for comet 1905 a, as pub- 

 lished in No. 4009 of the Astronomischc Naclirichten, is 

 given below. A set of elements and an ephemeris similar 

 to those obtained by Dr. Strbmgren have been computed 

 at the U.S. Naval Observatory, from observations made 

 on .March 26, 27, and 28, and are published in the same 

 journal. 



Ephemeris 12/1. (Berlin M.T.). 

 1903 « 5 log r log A Bright- 



April IS ... 7 8 22 ... -1-33 47-9 ... 0-0590 ... 9-8855 ... 0-87 

 17 -.7 18 24... +35 38-6 



19 ... 7 28 42 ... 4-37 22-7 ... 00638 ... 9-8988 ... o-8o 

 21 ...7 39 16 ... -f3S 59-8 



23 ... 7 50 6 ... -(-40 29-8 ... 0-0699 ■■■ 99139 •■. 0-73 

 Brightness at time of discovery (March 26) =1.0. 

 NO. 1850, VOL. 71] 



The following magnitudes have been estimated by 

 various observers at the times named : — 



h. m. mag. 



March 28 ... 7 59-6 (Geneva M.T.) ... 11-5 



29 ... 8 282 (Vienna „ ) ... 13-0 



April I ... 9 6-3 (Bamberg ,, ) ... ii-o 



On the last mentioned date Prof. Hartwig found that 

 the comet was circular, about 3' in diameter, and had a 

 scattered nucleus. 



Variability of a Minor Planet. — A telegram from 

 Prof. Pickering, published in No. 4009 of the Astrono- 

 mische Nachrichien, announces that Prof. Wendell has 

 discovered a variation of 0-5 magnitude in the brightness 

 of the minor planet (15) Eunomia. 



This is one of the asteroids situated at an intermediate 

 distance from the sun, and having a revolution period of 

 1570 days. 



N'isuAL Observ.ation of Jupiter's Sixth Satellite. — A 

 further visual observation of Jupiter's sixth satellite has 

 been made at the U.S. Naval Observatory with the 26-inch 

 refractor. 



Observing on January 8, Mr. Hammond made a search 

 for the recently discovered satellite in the position com- 

 puted from the Lick photographs, and there found a very 

 faint object, which, from its movement in relation to a 

 neighbouring star, proved to be the object sought. 



Real Path of a Bright Meteor. — From a large number 

 of observations made in south-west Germany, Herr H. 

 Rosenberg has calculated the real path of an exceptionally 

 bright meteor which was seen at 8h. 22m. (central Euro- 

 pean time) on March 21, 1904, and emitted about one- 

 quarter of the light given by the moon at full. 



After giving the details of the times and places of the 

 various observations, he deduces the following values for 

 the actual path of the object. Length of path 385 km., 

 duration of flight about g seconds, mean velocity 428 km. 

 per second, mean velocity relative to the earth 41-4 km. 

 per second. The average absolute height of the path 

 above the earth's surface was about 30 km. Other de- 

 ductions are made concerning the actual size, brightness, 

 parabolic velocity in space and actual path, and the follow- 

 ing value is obtained for the radiant point : — long. = 23° 8', 

 lat. = -f9° 10' {Astronomische Nachrichien, No. 4008). 



A New 24-iNCH Reflector at Harvard. — In No. 93 of 

 the Harvard College Observatory Circulars Prof. E. C. 

 Pickering announces that the construction of the new 

 24-inch reflector — one of the chief acquisitions with the 

 Anonymous Fund of 1902 — is now so far advanced that the 

 instrument may be used for visual observations. The 

 mirror was made by Messrs. Alvan Clark and Sons, and 

 the mounting has been designed and constructed in the 

 observatory workshop. 



Magnitude observations of three of the variable stars 

 discovered by Miss Leavitt near the Orion nebula have 

 been made with this instrument, and their variability con- 

 firmed, by Mr. L. Campbell, and the results are set out in 

 detail in the Circular. 



Stars with Variable Radial Velocities. — A list of nine 

 spectroscopic binaries discovered with the Mills spectro- 

 graph, in addition to the forty-eight previously announced, 

 is given in No, 70 of the Lick Observatory Bulletins. 

 Amongst them we find a Andromedfe, which was 

 announced as a binary by Mr. Slipher in 1904, and which 

 the Lick spectrograms show to have a negative radial 

 velocity varying from 2 km. (October 5, 1903) to 36 km. 

 (November 30, 1903). C Ceti has a small but undoubtedly 

 real variation, whilst 7 Geminorum shows a variation from 

 — 17 km. (on October 24, i8gg) to —4-7 km. (on January 

 27, igo4). Twenty-five spectrograms of the brighter com- 

 ponent of Castor, a" Geminorum, indicate a variation of 

 about 26 km. in the radial velocity. Applying the values 

 determined to Prof. Doberck's orbit of Castor, a pre- 

 liminary value of o"os is found for the parallax of this 

 star ; but this has not very great weight, owing to the 

 uncertainty in the elements of the visual system. 7) Bootis 

 with a period of several years, ( Serpentis with a prob- 

 ably short period, C Lyr;e, t Sagittarii, and 71 Aquilie 

 are the other stars for which variable radial velocities have 

 been discovered. 



