SCIENCE-GOSSIP. 



113 



ASTRONOMY, 



Conducted by Alice Everett, M.A. 

 (Hon. Secretary of the British Astronomical Association.) 









Rises. 



Sets. 



Position. 









A.M. 



P.M. 



R.A. 



Dec. 









h.m. 



h.m. 







Sun 



. July 



2 



... 3-49 ■ 



. 8.17 



.. C.46 . 



. 2f 2' N. 







16 



... 4.3 . 



. 8.8 

 Souths. 



A.M. 



• • 7-43 • 



. 21° 2l' 



Moon 





16 



... 2.6 . 



Souths. 



P.M. 



... II.24 • 



Rises. 



A.M. 



. II. 15 



Sets. 



A.M. 



• 245 



Souths. 



P.M. 







Mercury.. 



. June 



30 



... 5-53 . 



• 1-43 



... 8.18 . 



. 18° 38' N. 





July 



10 



... 5-39 • 



. 1.7 



.. 8.21 . 



• 15° 55' 





" 



20 



... 4-39 • 



. 0.5 



A.M. 



.. 7-55 •• 



. i5 3 46' 



Venus .. 



,, 



I 



... 1.40 . 



■ 9-23 



.. 4.1 .. 



■ 18 37' 





,, 



II 



... i-35 • 



• O.33 



.. 4-5° ■• 



. 20° 49' 





" 



21 



... 1.37 • 



P.M. 



■ O.44 



.. 5-40 . 



. 22° 10' 



Mars 



„ 



I 



... II.48 . 



• 5-46 



.. 0.23 . 



. 0' 43' S. 





„ 



II 



... II. 19 . 



• 5-29 



.. 0.46 .. 



. i° 29' N. 





" 



21 



... IO.5O . 

 A.M. 



. 5. II 



.. 1.7 ■ 



• 3 d 30' 



Jupiter 



,, 



I 



... 2.27 . 



. IO.39 



.. 5.16 . 



. 22^ 38' N. 







21 



... 1.25 • 

 P.M. 



• 9-39 



P.M. 



•■ 5.35 • 



. 22° 55' 



Saturn .. 



June 



30 



... 1.0 . 



A.M. 



• 6.37 



.. 13.12 . 



• 4° 54' S. 





July 



20 



... H.45 • 

 P.M. 



• 5-21 

 P.M. 



.. 13-14 • 



• 5 3 13' 



Uranus ... 



June 



30 



... 3-15 ■ 



. 8.1 



.. 14-36 - 



. 14° 54' S. 



Juno ... 



July 



13 



... — . 



• 7-5 



.. 14-31 •• 



. i° 0' S. 









Moon. 







3rd Qr. .. 



June 



26... 



10.3 a.m. 



New .. 



■ July 3 • 



.. 5.46 a.m. 



1st (Jr. .. 



July 



9 .. 



10.15 p.m. 



Full .. 



• July 17 • 



. 10.3 p.m. 



ir& Qr. ... 



11 



25... 



9.7 p.m. 









OCCULTATIONS OF STARS BY THE MOON. 



Dale. Star. 



July 17 A Sagittarii 



,, 20 50 Aquarii 



,, 21 b.a.c. 7835 



,, 25 19 Arietis 



A ngle A ngle 



Disappear- from Re-appear- from 

 Mag. ance. N. Pt. ance. N.Pt. 

 ... 5 8.42 p.m. 55 ... 9.52 p.m. 286° 

 ... 6 10.33 P-ni. 354° ... 10.57 p.m. 315° 

 ... 6J 2.1 a.m. 47 3 ... 3.20 a.m. 241 

 ... 6 11.30 p.m. Co 3 ... 12.25 a.m. 243' 



NEAR APPROACH. 



July 18, b.a.c. 7197, 6th mag., at 8. 55 p.m., angle 346°. 



The Sun. — The spots afford a field for study, 

 though there is reason to suppose that the solar 

 activity so conspicuously shown during the last 

 two years is on the wane. 



The Moon. — On July 3rd, the day of New- 

 Moon, our satellite will set about an hour after 

 the Sun. It may be possible, under favourable 

 circumstances, and with the aid of a good opera- 

 glass, to make out the thin crescent when its age 

 is only about fifteen hours. 



Mercury will be invisible to the naked eye after 

 the first three or four days of July. 



Mars is traversing the constellation Pisces. 



Jupiter may be seen in the morning in Taurus, a 

 little to the north-east of the bright star Aldebaran. 



Saturn is in Virginis about 5' north of the first 

 magnitude star Spica, and close to and east of the 

 star e Virginis (fourth magnitude). 



Venus is in Taurus and later will be in the 

 constellation Gemini. About July 7th, there will 

 be an interesting conjunction of this planet with the 

 first magnitude star Aldebaran, Venus lying 3^ 45' 

 north of the star. .Venus rises about two o'clock 

 in the morning. 



Uranus cannot be seen with the naked eye. It 

 lies in Libra, slightly to the west of the stars a, n 

 and 5 of this constellation. 



Neptune is not now visible. 



The small planets Vesta and Ceres will be in 

 conjunction on July 12th, Ceres lying about 2° 30' 

 to the north of Vesta, and for a month the two 

 will be close neighbours and pursue parallel 

 paths. 



The Canals of Mars. — Mr. J. R. Holt, of 

 Dublin, has put forward a new theory as to the 

 origin of the canals. He supposes that the funda- 

 mental difference between the cases of the Earth 

 and Mars is as follows : — In Mars a thin crust 

 was early formed and ruptured, the "canals'' 

 being the fissures formed by the rupture. The gas 

 then escaped and the fissures served as vents for 

 the internal volcanic energy, so that the crust has 

 remained almost in its primitive condition ever 

 since. On the Earth the crust was not formed so 

 early ; in consequence it escaped rupture as a 

 whole and w-as able to compress the gas. The 

 volcanic energy, not having any preformed vents, 

 deformed the crust considerably, and formed vents 

 for itself here and there. These, however, were 

 insufficient to allow of a complete escape ; in con- 

 sequence the surface has suffered from volcanic 

 action to an amount contrasting considerably with 

 the case of Mars. 



A Floating Telescope. — In the May issue of 

 " Knowledge," Sir Howard Grubb has an article 

 describing a plan for floating the greater part of 

 the tube of a large reflecting telescope in a great 

 tank, which he thinks would enable the instrument 

 to be mounted with sufficient stability for purposes 

 of celestial photography. Sir H. Grubb considers 

 it is now an important problem to overcome the 

 difficulties of mounting, which have heen an 

 obstacle in the way of using large reflectors, as, he 

 says, it is not likely that in the future it will 

 be possible to get discs of optical glass of sufficient 

 size to construct an object glass for a refractor, 

 which would equal in light grasping power such 

 an instrument as Lord Rosse's six-foot reflector. 



A New Triple Achromatic Object-Glass. — 

 At a recent meeting of the Royal Astronomical 

 Society, Mr. H. Dennis Taylor described a new 

 and "perfectly achromatic " object-glass, which he 

 has for some time been engaged in perfecting. It 

 consists of three lenses of three different kinds of 

 glass, all made by Schott, of Jena. By " perfectlv 

 achromatic," Mr. Taylor explained that he meant 

 that the chromatic aberration to be expected in an 

 objective of two feet aperture is no greater than 

 that introduced into a reflector whose focal length 

 is seven and a half times its aperture, when a one- 

 inch Huyghenian eye-piece is used. Messrs. 

 Cooke and Sons guarantee the permanence of 

 objectives made on this plan 



