Oct. ii, 1888] 



NATURE 



577 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1888 OCTOBER 14-20. 



/"C*OR the reckoning of time the civil day, commencing at 

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



is here employed.) 



At Greenwich on October 14 



Sun rises, 6h. 25m. ; souths, Ilh. 45m. 54'5s. ; sets, I7h. 7m. : 



right asc. on meridian, 13I1. 197m. ; decl. 8° 25' S. Sidereal 



Time at Sunset, l8h. 42m. 

 Moon (Full on October 19, 2ih.) rises, 15I1. 33m. ; souths, 



2oh. 13m.; sets, ih. im.*: right asc. on meridian, 2ih. 48 "6m.; 



decl. 15° 42' S. 



* Indicates that the rising is that of the preceding evening and the setting 

 that of the following morning. 



Occultatiotis of Stars by the Moon (visible at Greenwich). 



Corresponding 

 angles from ver- 

 tex to right foi 

 inverted image, 

 o o 



... 66 49 

 ... 203 — 

 ... 63 338 



Oct. 



16 . 

 16 . 

 20 . 



Oct. 

 20 



Star. 



74 Aquarii 

 B.A.C. 8214 

 fi Ceti 



Mag. 



. 6 

 . 6\ 



■ 4 



Disap. 

 h. m. 



o 57 

 21 21 

 23 39 



Reap. 



O 4lt 



h. 

 21 



t Occurs on the following morning. 

 ... Mercury stationary. 



Variable Stars. 



Star. 



R.A. 



U Cephei 



Mira Ceti 



T Monocerotis .. 

 U Geminorum' ... 

 R Camelopardalis. 



T Ophiuchi 



U Ophiuchi 



Z Sagittarii 



8 Lyrse 



R Lyrae , 



n Aquilae 



T Vulpeculae 



Y Cygni 



o 52-4 .. 

 2 137 .. 



6 19*2 .. 



7 48-5 •• 

 14 261 .. 



16 27-3 .. 



17 10*9 .. 



18 14-8 .. 

 18 46-0 .. 



18 51-9 .. 



19 46*8 .. 



20 467 .. 

 20 47 6 .. 



Decl. 



81 16 N. 



3 29 S. 



7 9N. 

 22 18 N. 



84 20 N. 



15 54 S. 

 1 20 N. 



18 55 S. 



33 14 N. 



43 48 N. 

 ■ o 43 N. 

 . 27 50 N. 

 • 34 14 N. 



Oct. 



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



M signifies maximum ; m minimum. 



Meteor- Showers. 

 R.A. Decl. 



h. 



16, 3 



15. 



18, 3 

 15. 

 17, 

 18, 



16, 19 



17, 19 



19, 22 

 18, 



20, 1 

 20, 23 

 14. 3 

 17, 3 

 20, 3 

 16, 23 



II m 



• M 



oM 



M 



M 



M 



46 m 



oM 



oM 



M 



oM 



oM 



o m 



o m 



o m 



o 1)1 



GEOGRAPHICAL NOTES. 



We notice in the last number of the Izvestia of the East 

 Siberian Geographical Society (vol. xix. 1), a most interesting 

 note, by L. A. Jaczewski, on the geological results of the last 

 Sayan expedition. The immense border-ridge of the great 

 plateau of East Asia, which stretches from the sources of the 

 Iya to Lake Baikal, was very little known. Many explorers 

 have visited the valleys of the Irkut and Oka which flow at 

 its northern base, but very few have crossed it, and if they 

 crossed the huge ridge, it was mostly to the north of Lake 

 Kosogol, where a broad passage is opened from the lowlands to 

 the high plateau. The Expedition of MM. Prein and Jaczews 



crossed it at three different places, and thus obtained an insight 

 into its geological structure. As to its age, it appears that lime- 

 stones, most probably Silurian, lie almost undisturbed at its 

 northern base, so that the hypothesis as to the great plateau 

 having been a continent since the Laurentian or Huronian 

 epochs is thus confirmed. We notice also that, besides 

 Munku Sardyk, 3500 metres high, there are in the Sayan at least 

 three or four summits of nearly the same height ; and that, viewed 

 from the south on the banks of the Kirlygoi stream, it appears 

 as a massive wall, 700 metres high, having a direction from the 

 north-west to the south-east. As to the complex ramifications 

 of the Sayan, they are chiefly due to a most extensive action of 

 atmospheric agencies, as was foreseen by Tchersky. Most 

 interesting observations were made as to the formerly quite 

 unknown glaciers of the northern slope, where they have the 

 shape of narrow glaciers descending down a very steep slope and 

 taking their origin amidst wide snow-fields. Their lower ex- 

 tremities reach a lower level than on the southern slopes. As to 

 the former extension of glaciers, which was maintained by Kro- 

 potkin, but doubted on account of prevailing theoretical concep- 

 tions as to the non-glaciation of Siberia, M. Jaczewski found 

 plenty of striae and striated boulders which made him consider 

 that glaciers formerly extended to a level of 1500 metres on the 

 northern slope, and 1 700 metres on the southern slope turned 

 towards the plateau. 



The French Maritime Survey is sending a special mission to 

 map the coasts of Madagascar. The officers will leave Paris in 

 a few days, and are busy at the St. Maur Magnetic Observatory 

 regulating their instruments for this purpose. 



ELECTRICAL NOTES. 



Prof. Fitzgerald (B. A. Address, Section A), in drawing 

 attention to Hertz's experiments, has done the greatest possible 

 service to electrical science. Hertz not only proves the existence 

 of the ether, but the fact that an electric field is due to the oscil- 

 latory motions of the ether. Everyone who has the means will 

 probably be repeating these experiments. The Electrician is 

 publishing a capital resume of Hertz's work by Mr. De Tunzel- 

 mann. Prof. Fitzgerald himself had predicted this result at 

 Southport in 1882, and Prof. Oliver Lodge has actually measured 

 these wave-lengths — the shortest ether wave measured being 

 3 yards — by extremely simple and beautiful experiments. 



Acheson (Nature, July 26, p. 305) is pursuing in Pittsburg 



his inquiry into the influence of the disruptive discharges of 



powerful alternating currents. He confirms his formula, 



E 3 x K 



= d, d being the sparking distance in inches and a a 



constant, and finds for 



Dielectric. Sparks between a. 



Air points . 135 



Air points and wire . 263 



Paraffin and cotton ... ,, . 5822 



Ozite and cotton .... ,, 7759 



Ozite is a residuum of petroleum. 



Lenard and Howard (Electrotechnik Zeitschrift, July 1888), 

 have succeeded in making flat spirals of pure bismuth which, in 

 the magnetic field, vary in resistance from 10 to 20 ohms, accord- 

 ing to the strength of the field, and form a good practical mode 

 of roughly measuring its intensity as suggested by Leduc. 



Dr. Borgman, of St. Petersburg (Phil. Mag., September 

 1888), has been experimenting on the transmission of electric 

 currents through air when flames or points are used as elec- 

 trodes. Some years ago, Prof. Hughes showed many of his 

 friends similar experiments with telephones, but for some reason 

 or other he has never published the results. The experiments 

 were extremely interesting, as indeed are those of Borgman, 

 who finds a difference in the surface resistance of the cathode 

 and anode flames. He attributes much to the influence of light 

 as studied by Hertz, Hallwachs, Wiedemann and Ebert, and 

 Arrhenius. These results have a very important bearing on the 

 new views of electrical action that are following from the 

 inquiries of Fitzgerald, Hertz, Lodge, and others. 



An extremely suggestive and very original paper was read at 

 the British Association by Prof. Hicks, "On a Vortex Ana- 

 logue of Static Electricity." Attractions, repulsions, lines of 

 force, charge, positive and negative electrification, induction, 



