December 1, 1897.] 



KNOWLEDGE. 



303 



ci'ossing and re-crossing on their silken ladders, they are 

 exceedingly peaceable ; but directly one has made a nest of 

 its own its true character develops, and should any of its 

 relatives tread upon ita entrance, death of the intruder is 

 the result. 



After thoroughly enjoying themselves the spiderlings 

 ascend to the highest point, and, facing the wind, raise 

 their bodies and spinnerets until the wind has caught the 

 silk and blown a small quantity out (mc Fig. 12). The 

 spiderling, on finding itself buoyed up, severs the con- 

 necting thread and is carried away on the wings of the 

 wind, sometimes to a great distance, where new colonies 

 arc formed. 



Those of my readers who are inclined to " think upon 

 these things " can find food for reflection ia this last ac' 

 of the life history of the Bi'itish trap-door spider, viz., the 

 first spiderling, after overcomiog the difficulties of ascent 

 from the nest, leaves behind it a straight silken ladder, up 

 which the second can climb without diflioulty ; it in its 

 turn adds its tiny thread ; the third does the same — un- 

 consciously it may be, but each one assisting its follower. 



Cannot students of nature do the same, by placing on 

 record one true fact, and so add to our knowledge of these 

 marvellous creatures about whose life history and economy 

 we know so little '? 



THE FACE OF THE SKY FOR DECEMBER. 



By Herbert Sadler, F.R.A.S. 



UNSPOTS are less frequent and are smaller in size 

 than of Idte, bat there are still some to be seen. 



Conveniently observable miuima of Algol occur 

 at llh 31m. p.m. on the 5th, at Sli. 2;!in. p.m. on 

 the 8th, at IOj. Gm. p.m. on the 28th, and at 

 Gh. Sim. P.M. on the 31st. 



Mercury is an evening star, but though he attains his 

 greatest eastern elongation (20') on the 21st;, his very 

 great southern declination (over 25" for nearly the first 

 half of the month) prevents any attempt at observation 

 in these latitudes. 



Venus is a morning star, but her great and increasing 

 southern declination militates agiiust her successful 

 observation ; she is not, moreover, a very attractive 

 telescopic object at the present. She rises on the 1st at 

 Gil. A.M., witli a southern declination at noon of IG' 58', 

 and an apparent diameter of lO.j", -i°/„ths of the disc being 

 illuminated. On the 7th she rises at Gh. 19m. a.m., wiih 

 a southern declination of 18' 57', and an apparent diameter 

 of lOj". On the 17th she rises at 6h. i8m. a.m., with a 

 southern declination of 21° 33', and an apparent diameter 

 of 10|". On the 2Mh she rises at 7h. 7m. a.m., with a 

 southern declination of 22° 45', and an apparent diameter 

 of lOf. After this she is too near the Sun to be visible. 

 During the month she describes a direct path through 

 portions of Libra, Scorpio, and Ophiuchus into Sagittarius. 



Mars is too near the Sun to be observed. 



The minor planet Ceres is in opposition to the Sun on 

 December 25th, with a stellar magaitude of 7'1. On the 

 1st she rises at 5h. 22m. p.m., witti a northern declination 

 at transit of 25° 37'. On the 11th she rises at 4h. 83m. 

 P.M., with a northern declination of 2G° 24'. On the 21st 

 ehe rises at 8h. 37m. p.m., with a northern declination of 

 27° 15 . On the 31st she rises at 2h. 41m. p.m., with a 

 northern declination of 28° 0'. During the month she 

 describes a retrograde path in Auriga, close to the northern 

 boundary of Gemini. 



Jupiter is a morning star, but as he rises just after 

 midnight at the end of the month we give a short 



ephemeris of him. Oa the 1st he rises at Ih. 48m. a.m., 

 with a southern decliaation at noon of 1° 18' south, and 

 an equatoriil diameter of 31|". Oj the 17th he rises at 

 Oh. 54m. A.M., with a southern decliniti^n ol 2' 3 , and an 

 apparent equatjriil diameter of 35^". O.i llio 31st he 

 rises at Oh. 7m. a.m., with a southern declinxtiou of 2' 31', 

 and an apparent equatorial diameter of 36.]'. l)a.-i:ig ihj 

 month he describes a direct path in Virg.j, betwj.in ■/) and 

 y Virginis. 



Both Saturn and Uranus are, for the pu.pj3e3 of the 

 ordinary observer, invisible. 



Neptune is well situated for observation, rising on the 1st 

 at 4h. 33m. p.m., with a northern declination of 21° 47', 

 and an apparent diameter of 26''. On the 11th he rises 

 at 3h. 52m. p.m., with a northern declination of 21° 40'. 

 On the 21st he rises at 3h. 13m. p.m., with a northern 

 declination of 21° 45'. O.i the 31st he rises at 2h. 32m. 

 P.M., with a northern declination of 21° 44'. During the 

 month he describes a short retrograde path in Taurus, in a 

 regio:i rather barren of naked-eye stars. 



December is a fairly favourable month for shooting stars, 

 the chief showers being those of the Geminids on 

 December 9th to 12th, the radiant point being in E A. 

 7h., and north declination 3'J°, rising at about 4h. lOm. 

 p.M , and setting at Ih. 4i)m. a.m. ; and of the Audrom-ides 

 oa the evenings of the 26th and 27th, the radiant point 

 being in Ih. 40m. R.A., and north declination 43°. 



The Moon enters her first quarter at 3h. 15m. a..m. on 

 the 1st ; is full at 4h. 54m. a.m. on the 9th ; enters her 

 last quarter at 4h. 22m. a.m. on the 17th ; is new at 

 7h. 55m. P.M. on the 23rJ ; and enters her first quirier 

 at 7h. 27m. p.m. on the 33th. The i\Ioou will be near the 

 Pleiades on the aftirnoon of th: 7th. 



(Kfjrgs Column. 



By C. D. LococK, B.A.Oson. 



Communications for this column should be addressed to 

 C. D. LococK, Burwash, Susses, and posted on or before 

 the lOth of each month. 



Solutions of November Problems. 



No. 1. 



(By A. C. Challenger.) 



Key-move— 1. Kt to Q4. 



Ifl. . . . KtoQ3, 2. Q to r.lch, etc. 

 1. . . . Kt to B3, 2. Q to Kt3ch, etc. 

 1. . . . Any other, 2. Kt to KlGjh, etc. 



No. 2. 

 (By G. .J. Slater.) 

 1. R to B8, and mates next move. 

 Correct Solutions of both problems received from 

 Alpha, J. T. Blakemore, and G. Coules. 



Of No. 1 only, from H. H. Thomas, W. de P. Crousaz, 

 M. Wiedhofft, Captain Forde. 



Of No. 2 only, from W. Clugaton, G. ti. Beazley. 



This problem has evidently some good tries. If 1. B 

 to BG (H. H. Thomas, W. de P. Crousaz, and Captain 

 Forde ), then 1. ... B to Bsq ! and there is no mate. 

 Again, if 1. B to Q4 (i\I. Wiedhofft), then 1. . . . PxP. 

 Lastly, if 1. P to Kt;4 (A. H. Dj, 1. . . . Q to E7, and again 

 there is no mate. 



W. ./, Ashdown. — Many thanks ; both appear on the next 

 page. 



