Feb. 16, 1 888 J 



NATURE 



381 



OUR ASTRONOMICAL COLUMN. 



Melbourne Observatory. — The Annual Report of this 

 Observatory, dated August 14, 1887, states that the buildings 

 and equipment of the Observatory were in good condition with 

 the exception of the mirrors of the great Cassegrain reflector, 

 which had become so dull as materially to interfere with the 

 observation of the fainter nebulae. It was proposed to substitute 

 mirror A, the less tarnished of the two, for mirror B, now in the 

 telescope, and either to have B repolished on the spot or to send 

 it to Dublin to be re-polished under the care of Sir H. Grabb. 

 The new transit circle was in excellent order, and 2487 right 

 ascensions and 1301 polar distances had been observed during the 

 year. Eighty-seven southern nebulae had been examined with 

 the great reflector, and four searched for, but not found. The 

 use of the photo-heliograph, which had been altered in July 

 1886, so as to take pictures on a scale of 8 inches to the solar 

 diameter, had been much interfered with by bad weather, and 

 only 121 photographs had been secured. The principal fresh 

 work proposed for the Observatory was the co-operation in the 

 photographic survey of the heavens ; the Victorian Government 

 having consented to the Observatory joining in that undertaking, 

 and having, placed ;(i^iooo on the estimates of the current year 

 towards the necessary expenditure. 



The American Nautical Almanac Office. — The Re- 

 port of Prof. Newcomb, Superintendent of the Office, for the 

 year ending 1887 June 30 has recently appeared. From this we 

 learn that the printing of the several Nautical Almanacs published 

 by the Office fell a little into arrear in 1887, the printing of the 

 American Ephemeris for 1890, which should, according to custom, 

 have appeared in June, not being quite ready in October. The 

 computations for the following years were in their usual slate of 

 forwardness. The principal part of the Report deals with the 

 new tables of the planets on which Prof. Newcomb and his 

 assistants are engaged. The work is divided into four sections — 

 viz. : (I.) The computation of the general perturbations of the 

 planets, the work now in hand relating to those of the four inner 

 planets ; on twelve of the fourteen pairs of planets which come 

 into play in this part of the undertaking, the work has already 

 been completed. The incomplete perturbations are those of 

 Venus and Mars by Jupiter. (II. ) The re-reduction of the older 

 observations, and discussion of the later ones, with a view of 

 reducing them all to a uniform system. In this section Maske- 

 lyne's Greenwich observations from 176510 i8ii, and Bradley'.*, 

 1750 to 1762, have been already reduced, the latter by Dr. 

 Auwers. Airy's Greenwich observations, the Paris observations 

 from 1800 as reduced by Leverrier, and Bessel's Konigsberg 

 observations, will need no discussion except that necessary to 

 reduce them to the adopted standard system. The re-reduction 

 of Piazzi's Palermo observations, 1 791-1813, is in hand, but it is 

 not yet decided as to whether Taylor's Madras observations should 

 be included. (III.) The computation of tabular places of the 

 planets from Leverrier's tables up to the year 1864 — the most 

 laborious and difficult part of the work — is in a fairly advanced 

 state. (IV.) The final discussion of the results. Prof. Newcomb 

 estimates that the equations of condition for correcting the 

 elements of the four inner planets will be ready for solution 

 towards the end of 1889, but they will involve extended dis- 

 cussion and comparison in order to get the results in the final 

 form for publication. Of the work on the four outer planets, 

 Uranus and Neptune are yet untouched ; but Mr. Hill's new 

 theory of Jupiter and Saturn is in the hands of the printer, and 

 Mr. Hill is now engaged in the construction of the tables and 

 ephemerides for finally correcting their elements. In connection 

 with the lunar theory, the principal work on hand is the com- 

 parison of Hansen's tables with observed occultations since 

 1750. Another branch of the planetary work is the determina- 

 tion of the mass of Jupiter from the motions of Polyhymnia : 

 the perturbations of the planet have been computed from its 

 discovery in 1850 to October 1888, and the work awaits the 

 observations during the approaching opposition to be brought to 

 a final discussion. 



ASTRONOMICAL PHENOMENA FOR THE 



WEEK 1888 FEBRUARY 19-25. 



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



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



is here employed.) 



At Greenwich on February 19 

 Sun rises, 7h. 9m. ; souths, I2h. 14m. 6'2S. ; sets, I7h. 19m. : 



right asc. on meridian, 22h. 97m. ; decl. Il° 22' S. 



Sidereal Time at Sunset, 3h. 15m. 

 Moon (at First Quarter February 20, 2h.) rises, loh. 25m. ; 



souths, I7h. 46m. ; sets, ih. i8m.* : right asc. on meridian, 



3h. 42'8m. ; decl. 14° 34' N. 



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

 that of the following morning. 



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



Corresponding 



angles from ver- 



Disap. Reap. tex to right for 



inverted image. 



h. m. h. m. no 



Feb. 



Star. 



Mag. 



GEOGRAPHICAL NOTES. 



At Monday's meeting of the Royal Geographical Society, the 

 paper read was by Mr. Randle F. Holme, on Labrador, which 

 he visited in July-October of last year. Mr. Holme succeeded 

 in penetrating into the heart of Southern Labrador, as far as 

 Lake Waminikapou, and not far from the Grand Falls, which 

 Mr. Holme believes will turn out to be the greatest falls in the 

 world ; but, as General Strachey pointed out in the discussion, Mr. 

 Holme's conception of the height is probably exaggerated. Mr. 

 Holme went from Newfoundland to Bonne Esperance on the south- 

 east coast of Labrador, and sailing northwards touched at several 

 points, proceeding up Hamilton Inlet and the Grand River, to the 

 point mentioned above. Mr. Holme found many difficulties in 

 the way, and much of the country he visited was virtually 

 unexplored. With regard to the height of the Grand Falls, Mr. 

 Holme states that the centre of Labrador, as is generally known, is 

 a vast tableland, the limits of which are clearly defined, though 



