March 7, 1878] 



NATURE 



363 



value will be seen in determining the curve of the diurnal 

 variation of the rainfall. We note, with much satis- 

 faction, the continued prosecution of the important inquiry 

 into the chemical climatology of Paris. 



Meteorology of Western Australia. — We have 

 recently received a most valuable addition to the meteo- 

 rology of Australia, which is being so energetically worked 

 out by Messrs. Todd, Ellery, Russell, and Macdonnell, in 

 the form of a tirst Report of the Meteorology of Western 

 Austraha, by Mr. Malcolm Fraser, Surveyor-General for 

 the Colony. The report contains a good summary of a 

 pretty complete set of observations made during the 

 whole of 1876 at Perth, and the barometric means for five 

 months at Point King Lighthouse, on the south coast. The 

 chief results are, for the summer months, mean monthly 

 pressure — st/gig inches, temperature 74°7, rainfall o"54 

 inch, and wind velocity in miles 404 ; and for the winter 

 months — pressure 30'i77 inches, temperature 57°"5, rainfall 

 4*90 inches, and wind velocity 280 miles. The lowest tem- 

 perature for the year was 34°7, and the highest 1 1 2°'o, on 

 February 20, and it may be noted that the mean daily 

 maxima for this month was as high as 93°7. Speaking 

 generally, the winds in summer blow from the sea inland, 

 and in winter from the land seawards, little rain falling 

 in the former season, whereas in the latter season the rain- 

 fall is copious but not excessive. The smallest rainfall of 

 any month was 0*04 inch in February, falling on one day, 

 and the largest 8'45 inches in June, falling on nineteen 

 days. It is contemplated to establish stations at Nickol 

 Bay, Champion Bay, and York ; but a still further exten- 

 sion of the system is required, not merely for the develop- 

 ment of the climatology of the colony, of which we may 

 be said to know next to nothing, but also from the 

 important bearing of the meteorology of Western Australia 

 on that of the whole continent of Australia, particularly 

 on the system of weather warnings for that group of 

 colonies. 



OUR ASTRONOMICAL COLUMN 



The Uranian Satellites, Ariel and Umbriel.— 

 We continue the ephemeris of the two interior satellites 

 of Uranus, making use of Prof. Newcomb's tables in the 

 appendix to the Washington Observations for 1873. The 

 positions and distances are for gh. Greenwich mean time, 

 when the planet will be near the meridian during the 

 period over which the ephemeris extends ; though these 

 are given for every evening, the presence of the moon in 

 this quarter of the heavens may interfere with observation 

 on or about March 16. 



The Transit of Mercury on May 6.— The Nautical 

 AlinanaciwxviviYits the usual elements of this phenomenon 

 and the times of the contacts and of least distance of 

 centres referred to the centre of the earth, with the neces- 

 sary formula; for reducing the moments of contact to any 



place upon the earth's surface. The following figures 

 result for Greenwich, Edinburgh, and Dublin ; Green- 

 wich mean times at the respective observatories : — 



First External First Internal 



Contact. Contact, 



h. m. .=. h. m. s. 



Greenwich 3 10 58 3 14 4 



Edinburgh 3 11 o 3 14 6 



Dublin 311 3 3 14 9 



The least distance of the centres (4' 47") takes place at 

 6h. 58'5m. and, as the sun will set at 7h. 29m., 7h. 47m., 

 and 7h. 36m. local mean times at these places respectively, 

 rather more than half the transit ,will be visible. The 

 final contacts may be well observed in America. 



The Radcliffe Observatory.— The Radcliffe Ob- 

 server is again punctual in the distribution of his volume 

 of Observations, Vol. xxxv., containing the work in the 

 year 1875, having been in the hands of astronomers 

 several weeks. The only new feature is the publication of 

 observations of the solar spots ; the distances from the sun's 

 limbs are fixed by transits and by readings of the decli- 

 nation circle of the heliometer ; descriptions and sketches 

 of the forms of the spots are included. Nearly 1,200 stars 

 were meridionally observed. At the end of the Intro- 

 duction, Mr. Main has exhibited the apparent errors of 

 Tabular R.A. of the moon's limbs, as given on the same 

 day by the observers at Oxford and Greenwich in 1863 

 and 1864, and from 1870 to 1S74 inclusive. As usual the 

 meteorological observations taken at the Radcliffe Obser- 

 vatory are published in considerable detail. 



The Harvard College Observatory, U.S.— Prof. 

 Pickering has issued a report of proceedings at this 

 observatory during the year ended November i, 1877, 

 with an outline of the course of observations intended to 

 be pursued in future with the 15-inch refractor and the 

 meridian circle, the telescope of which has an aperture of 

 eight inches. The newly-discovered satellites of Mars 

 have been the objects to which most attention has been 

 directed with the refractor, the observations consisting 

 not only in a series of measures of positions and distances 

 which Prof. Pickering believes to be second only to the 

 very complete series obtained by the discoverer with the 

 large Washington instrument, but in a numerous series of 

 photometric comparisons with the planet on methods 

 explained in the Report, by which the image of Mars was 

 brought to the same degree of brightness as each satellite. 

 It was remarked under favourable opportunities for com- 

 parison that the outer satellite did not partake of the red 

 colour of Mars, which Prof. Pickering observes is " a 

 curious result, and having an important value in any 

 theory of the cause of the peculiar colour of Mars." The 

 observations were not wholly reduced at the time the 

 Report was issued, but an approximate reduction gave the 

 diameter of the outer sateUite about 5*9 miles, and that of 

 the inner one, 6"5 miles. " As the darker colour of the 

 outer satellite somewhat diminishes its hght," it was con- 

 sidered safe to call it about six miles in diameter, and the 

 inner satellite seven miles. These comparisons were made 

 between August 27 and October 12. A large number of 

 similar measurements of seven of the satellites of Saturn, 

 including the very faint object, Hyperion, have also been 

 obtained. Remarking that other classes of observation 

 appear to be well cared for at various observatories in the 

 United States (Dr. Peters being engaged in the determin- 

 ation of the small stars near the ecliptic, at Clinton ; the 

 great telescopes of Washington, Chicago, and Cincinnat/. 

 being used almost exclusively for micrometric measures ; 

 spectroscopy being the intended Une of observation at 

 Princeton College ; and the telescopes of Mr. Rutherford 

 and Dr. Draper being largely used for photographic pur- 

 poses), Prof. Pickering intends to devote the Harvard 

 refractor mainly to photometry .as "a field almost wholly 

 unexplored with large telescopes," in America or else- 

 where. The meridian-circle appears to have b^en chiefly 



