April s, 1888] 



NATURE 



545 



This law comprises two inequalities, with the periods respec- 

 tively of I4i'3 years and 377, and coefficients of 173*3 ^"d l8"o 

 minutes of time. A third period of 17 years, with a coefBcient 

 of 3'5 minutes, was suspected, but the coefficient is so small as to 

 bring it almost within the limit of errors of observation. The 

 resulting elements are as follow: 1888 January 3, 7h. 21m. 

 29"23s. ..(G.M.T. ) + 2d. 2oh. 48m. 55'425s. E' -f I73"3m. 

 sin. (-uV E' + 202° 30') + i8"om. sin (^jt E' + 203° 15') + 3'5m. 

 sin (J- E' + 90° 20') ; where E' = E (Schonfeld) - 11210. The 

 interpretation of the theory is as follows : — The period at the 

 time of Goodricke's discovery of the character of the variation 

 was 2d. 20h. 48m. 58 "OS., lengthening to 59'8s. in 1798, 

 diminishing again in the next ten years to 57 ■2s., and then 

 again lengthening irregularly to 59'2s. in 1830. A rapid 

 diminution shortly followed, and the rate was reduced to 54 'Os. 

 in 1843. After a halt a further but less rapid diminution set in, 

 and in 1858 the period was 5285. The following six years saw 

 an increase of l "63., followed by another shortening, until in 1877 

 the period had fallen to 51 "is., from which time it has remained 

 ■ nearly constant ; but should the theory be correct, a period of 

 increase must shortly set in, which, with halts and retrogressions, 

 will attain a maximum somewhat late in the coming century. 



The paper concludes with a table of heliocentric times of 

 minima up to August 1898. 



M. Oudemans, Director of the Utrecht Observatory, is like- 

 wise preparing a work on this variable, and requests observers 

 to transmit to him copies of their notes on all observed minima 

 since 1883. 



Observations of Variable Stars. — Mr. Edwin Sawyer 

 has given, in Nos. 164 and 165 of GonhC s y ournal,\\\% observa- 

 tions of several variable stars made during the year 1886. The 

 following table will show how some of these compare with the 

 ephemerides given week by week in Nature. 



Star. 

 V Cancri 

 R Ursae Majoris 

 R Virginis 

 S Coronse 

 R Scuti 



Phase. 



M . 



M . 



M . 



M . 

 m 



M . 



Observed. 

 1886 March 29 

 1886 April 29 

 1886 April 8 

 1886 May 10 

 1886 July 21 

 1886 Sept. 12 

 1886 Dec. 2 



Calculated. 

 April 12 

 May 12 

 April 10 

 April 10 

 June 27 

 Aug. I 

 Nov. 17 



Mira Ceti was observed at maximum 1886 January 9 ; g (30) 

 Herculis at minimum June 14, and at maximum September 20 ; 

 and W Cygni at three ei^ochs, viz. m July 8, M September 10, 

 and 111 November 5. 



Gore's new variable near Xi Orionis, to which Mr. Sawyer 

 gives the lettering U Orionis, but which other astronomers have 

 generally designated T, attained a maximum about 1887 De- 

 cember 14. The maximum was only a feeble one, -7*5 mag. 

 The light remained almost stationary from 1887 November 29 

 to 1888 January 2, a period of thirty-four days. The period of 

 the star must be almost exactly a year. 



The variable Lai. 40083, discovered by Mr. S. C. Chandler 

 (see Nature, vol. xxxv. p. 282), and to which he has given the 

 name X Cygni, has shown from further observation that its 

 light-curve is not constant in different periods, the minimum 

 brightness being especially variable, but since the bright and 

 faint minima do not alternate regularly the star does not belong 

 to the /3 Lyrae class. Mr. Chandler's revised elements for the 

 star are as follow: i886 October 13, i4h. 20m. G.M.T. -f 

 I5d. I4h. 24m. E. Approximate duration of increase 5*6 days, 

 of decrease 10 o days. The maximum brilliancy is generally 

 about 6 •4m. J the minimum ranges from 7 •2m. to 77m. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1888 APRIL 8-14. 



/"pQR the reckoning of time the civil day, commencing at 

 ^ Greenwich mean midnight, counting the hours on to 24, 



is here employed. ) 



At Greenwich on April 8 

 Sun rises, 5h. 20m. ; souths, I2h. im. 43 •3s.'; sets, i8h. 43m. : 



right asc. on meridian, ih. 104U1. ; decl. 7° 29' N. 



Sidereal Time at Sunset, 7h. 53m. 

 Moon (New on April 11, 9h.) rises, 4h. 46m.; souths, 



loh. 6m.; sets, I5h. 35m.: right a^c. on meridian, 



23h. i4-6m. ; decl. 8° 21' S. 



Planet. 



Mercury.. 

 Venus ... 

 Mars ... 

 Jupiter ... 

 "^aturn ... 

 Uranus... 

 Neptune.. 



Rises, 

 h. m. 



4 52 

 4 47 



22 57^ 



10 59 



18 9 



6 56 



Souths. 



h. m. 

 10 29 

 10 32 



O 22 



3 10 



18 58 

 23 46 



14 37 



Sets. 

 h. m. 

 16 6 .., 

 16 17 ... 



5 51 ••• 

 7 23 . 



2 57*-- 



5 23*... 



22 18 ... 



Right asc. and declination 

 on meridian, 

 h. m. . . 



* Indicates that the rising is that of the precedii; 

 that of the following morning. 



23 37 'o 

 23 40 "9 

 13 286 

 16 169 



8 78 

 12 56*4 



3 457 



5 8S. 

 3 40 S. 



6 48 S. 

 20 19 S. 

 20 48 N. 



5 17 S. 

 18 11 N, 



evening and the setting 



April. 



8 



II 

 14 



h. 

 23 



Mercury in conjunction with and l" 16' north 



of the Moon. 

 Venus in conjunction with and 2' 24' north 



of the Moon. 

 Mars in opposition to the Sun. 

 Mercury in conjunction with and 1° 10' south 



of Venus. 



Variable Stars. 



Star. 



U Cephei 



Algol" 



R Canis Majoris... 

 U Monocerotis ... 



S Cancri 



S Librae 



U Ophiuchi 



W Sj^ittarii 

 Z Sagittarii... 

 U Sagittarii ... 



R.A. 



Decl. 



O 52*4 ... 81 16 N. 

 3 0-9 ... 40 31 N. 



Apr. 



7 I4'5 



7 25-5 



8 37-5 

 14 55 o 

 17 io*9 



16 12 S. 



9 33 S. 

 19 26 N. 

 8 4S. 

 I 20 N. 



17 57"9 ••• 29 35 S. 



18 14-8 ... 18 55 S. 

 18 25*3 ... 19 12 S. 



17 Aquilae 19 46-8 ... o 43 N. ... ,. 



T Vulpeculae ... 20 467 ... 27 50 N. ... ,, 

 R Vulpeculas ... 20 59*4 ... 23 23 N. ... ,, 



5 Cephei 22 25*0 ... 57 51 N , 



M signifies maximum ; ni minimum. 



Meteor- Showers. 

 R.A. Decl. 



Near o Ursa; Majoris 

 ,, 42 Herculis... 



163 



248 



60 N. 

 50 N, 



April 10 and II. 



GEOGRAPHICAL NOTES. 



A SHORT excursion into the almost unknown interior of San 

 Domingo was made last summer by Baron H. Eggers,in the course 

 of which he explored the mountainous district, and made a com- 

 plete study of the vegetation of this elevated region; he further dis- 

 covered a route along which the exploration of this little-known 

 mountain region may be carried out with facility. The following 

 details are taken from the traveller's own account of his journey, 

 published in Petermann s Mitteilungen (Part 2, 1888). He left 

 Puerto Plata, on the north coast, on May 2 last, and about the 

 middle of the same month found himself at Jarabacoa on the Rio 

 Yagin, having passed through Santiago on his way. While at 

 Jarabacoa he ascended Monte Barrero (4100 feet) in the vicinity 

 of the town. The steep slopes of this peak are covered with 

 lofty pine woods. In the small ravines and between rocks the 

 traveller observed many interesting plants, e.g. the dark red 

 Fuchsia triphylla, a bright red Siphocainpylos, a large Penta- 

 rhaphia, and a beautiful Cyathea ; he also found a large number 

 of hitherto unnoticed plants, including an ilex, several Compositae, 

 Labiatae, &c. The animal life in these pine forests appears to be 

 very poor : there are scarcely any insects, and a species of crow 

 is the only bird seen. At the end of May the traveller with a 

 small party of blacks set out in a due southerly direction for the 

 Valle de Constanza. The valley is well watered, and its height 

 above the sea is 3840 feet. Its inhaiiitants, numbering 100, are 

 engaged in cattle-rearing, and the cultivation of beans, maize, 

 cassava, tobacco, 6:c. The climate is cool, and from November 

 to March dry ; during the rest of the year it rains. The ther- 

 mometer at 6 o'clock in the morning of May 28 stood at 59" F. 

 The higher part of the surrounding mountains, which almost 

 everywhere contain gold, though in small quantities, are quite 

 unexplored. From the Valle de Coustanza the traveller made a 



