3o8 



NA TURE 



{Jan. 2;, 1SS7 



that the most probable period is one of id. iih. 59m., or if not 

 that, 20h. 34m., or possibly i8h. 6m. The following table shows 

 that tlie shorter the period of the variable, the higher is the ratio 

 which the period of oscillation bears to it. In the present star 

 the oscillation probably occupies about six hour^ ; a period so 

 great as three days or much shorter than one day wouUl make it, 

 therefore, an exception to the rule followed by the other seven 

 stars of the same order. 



Star Period Oscill.llion Ralio 



U Ophiuchi 



8 Librae 



U Cephei 

 Algol ... 



U Coronse 



A Tauri 



S Cancri 



2013 



55 -^S 

 59-82 

 68 -8 1 

 82-85 

 94-87 

 227-63 



5'o 

 12-0 

 lo-o 



9-15 



975 

 lo-o 



215 



0-248 



0214 

 0-167 

 0-134 



OII8 

 0-105 

 0-094 



The variable was discovered by Mr. Chandler and not by 

 Dr. Gould as at first reported. 



Mr. Espin, in Circular No. 12 of the Liverpool Astronomical 

 .Society, notes the variability of a star om. 35s. p and 0° 8' n of 

 fi' Tauri. It is probably a variable of long period ranging from 

 gm. ± to below 1 2 m. Its place for 1885 o is R. A. 4h. 21m. 25s., 

 Decl. 15° 5o'-7 N. 



The Washington Observatory. — The Annual Report of 

 the U.S. Naval Observatory, dated October 30, 1SS6, has re- 

 cently been issued. Commodore G. E. Belknap, who was 

 Superintendent of the Observatory at the date of the last Report, 

 retired from that post on June 7, and was succeeded by Com- 

 mander Allan D. Brown, who therefore is the writer of the 

 Report now before us. In connection with the Chronometer 

 and Time-Service Department, under Lieut. S. C. Paine, it is 

 remarked that the time-service continues to increase in popa 

 larity; and its usefulness is daily becoming more apparent to the 

 public. The time-balls that have been established have been 

 much appreciated, and are of great value to the shipping and 

 commercial interests. Much attention appears also to have been 

 given to the chronometer trials, it evidently being the desire of 

 the Observatory to afford makers every assistance in its power 

 in obtaining data that will tend to the improvement of chrono- 

 meters. The 26-inch refr.-.ctor, in charge of Prof. Asaph Hall, 

 has been used in observations of satellites, of double stars, and 

 of Saturn. Observations of stellar parallax have also been 

 made. The reduction of the observ.ations of lapetus and of 

 the six inner satellites of Saturn, as well as those for stellar 

 parallax, have been completed, and the results published. The 

 transit-circle has been employed in observations of stars of the 

 American ephemeris, of the sun, moon, and planets, and such 

 miscellaneous stars as were necessary to complete the data for 

 the proposed transit- circle Catalogue. The whole number of 

 observations since the last Report has been 5180. The reduc- 

 tions have also been proceeded with as rapidly as possible. The 

 instrument remains in charge of Prof J. R. Eastman. Photo- 

 graphs of the sun have been taken -with the photo-heliographic 

 apparatus lately belonging to the Transit of Venus Commission, 

 whenever practicable. The work was commenced on Januaiy 11, 

 18S6 ; and up to and including September 30, 1886, there have 

 been obtained ninety-eight negatives showing spots on the sun's 

 surface. Hitherto no photographs have been taken, except w-hen 

 the sun showed spots on his disk, and then one only near noon. 

 This work has been intrusted to Ensign A. G. Winterhalter, 

 who hopes that in the future the number of photographs in a 

 given period will be considerably increased, better arrangements 

 having been made for securing them between lo a.m. and 2 

 p.m. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1887 JANUARY y,— FEBRUARY 5 

 ( trOR the reckoning of time the civil day, commencing at 

 Greenwich mean midnight, counting the hours on to 24, 

 is here employed. ) 



At Greenwick on Jamtary 30 

 Sun rises, 7h. 44m. ; souths, I2h. 13m. 3 1 -8s. ; sets, i6h. 43m. ; 

 decl. on meridian, 17° 39' S. : Sidereal Time at Sunset, 

 ih. 2lm. 

 Moon (at FirsL Quarter on February i ) rises, loh. 23m. ; souths, 

 l6h. 50111. ; sets, 23h. 27m. ; decl. on meridian, 4" 40' N. 



Planet 



Rt! 



Mercury ... 7 46 



Venus 8 25 



.Mars 8 31 



Fupiter o 35 



Saturn 14 29 



* Indicates that the setting is that of the folowing mornine'. 



OccitUations of Stars by the Moon (visible at Greenwich) 



Corresponding 

 T c n* T>- D angles from ver- 



Jan Star Mag. Disap. Reap. tex to right for 



inverted image 



;' Piscium 



44 



21 24 



48 Tauri 6 ... I 15 .. 



B.A.C. 1526 ... 6 ... 18 26 .. 

 Variable Stars 

 tar R,A. Decl. 



2 9 

 19 24 



185 289 



150 300 

 122 233 



R Andromedse 

 U Cephei ... 



o 18-1 ... 37 57 N. 

 o 52-3 ... 81 16 N. 



Algol 3 0-8 ... 40 31 N. 



f Geminorum ... 6 574 ... 20 44 N. 



5 Librs 14 54-9 ... 8 4 S. 



S Serpentis 15 16-4 ... 14 43 N. 



U Ophiuchi 17 io-8 ... i 20 N. 



Jan. 31, o o m 



., 31, 22 o m 



Feb. 5, 21 39 ?« 



,, 5, 4 23 >« 



,, I, o o M 



,- 3. I 49 m 



:, 4. ^ 



Jan. 30, 4 16 m 



/3 Lyrse 



5 Cephei 



j1/ signifies 



and at intervals of 20 8 



iS 45-9 ... 33 14 N. ... Feb. 4, 19 o »«2 



22 25-0 ... 57 50 N. ... ,, 4, I o M 



2 secondary t 



GEOGRAPHICAL NOTES 

 In connection with Major Macgregor's paper on his journey from 

 Upper Assam to the Irrawadi, read at a recent meeting of the 

 Royal Geographical Society, and printed in the new number of 

 the Proceedings, Dr. G. Watt made some valuable remarks on 

 his own observations in the Manipur district. Manipur is a 

 small valley surrounded by mountain-ranges, and in this valley 

 the rainfall was found to be only about 39 inches, but seventeen 

 miles off, in the mountains which formed the north-east ranges, 

 the rainfall was as much as 120 inches, and towards the Naga 

 country to the north it became greater and greater in certain 

 limited tracts. In the Khasia Hills 600 inches might fall in 

 one place, and twenty miles off only 50 inches. Nothing in 

 Manipur struck Dr. Watt so much, as a botanist, as the remark- 

 able transitions of vegetation in that small region. Dr. Watt 

 gathered twelve or more species of oaks, many of which were 

 new to science, and ten or twelve species of rhododendrons, in 

 Manipur alone. The Rhododendron Falconeri, found in the Naga 

 Hills by Sir Joseph Hooker, is nowhere met with in the immense 

 tract between the Naga Hills and Sikkim. This and the 

 epiphytic R. Dalhousia, which grows on a hill thirty miles north 

 of Darjeeling, Dr. Watt found in the Naga Hills at an altitude of 

 6000 to 8000 feet, and these rhododendrons never occur in Sikkim 

 below 10,000 to 13,000 feet. There were many instances of 

 plants falling in their altitude as the traveller passed to the east 

 and south-east from Sikkim, until at Moulmein a rhododendron 

 was found growing near the sea, a circumstance which was not 

 met with in any other part of Asia. There is something in that 

 region which, apart from pure geography, is of vital interest. 

 Sarameti, which is under 13,000 feet high, the natives said, had 

 snow all the year round, whereas on the Himalayas the lowest 

 point at which snow occurs is 17,000 feet. In Manipur, the 

 whole valley, 3000 feet high, was covered with hoar-frost in 

 December. Dr. Watt thought this was a point that should be 

 thoroughly investigated : what is the cause of this falling in 

 altitude in the vegetation ? General Strachey, who was in the 

 chair, considered that the peculiarities of the vegetation of 

 Manipur compared with Assam were connected with the evident 

 lo-n-ering of temperature indicated by the low snow-line. There 

 could be no doubt that the warm currents of air coming up the 

 valleys of the Irrawadi and the Salween and meeting the snowy 

 mountains to the north produced an enormous precipitation of 

 rain, which during winter fell as snow. The consequence seemed 

 to be that there was snow there at a very much lower level than 

 in the mountains further to the north. That an immense 

 quantity of rain fell in the upper portions of the valley of the 



