62 



SCIENCE. 



[Vol. IY. No. 76. 



all observations are to be reduced and published 

 without delay." 



The fundamental instrument, the transit circle, 

 has been kept well at work on the regular observa- 

 tions of the sun, the moon, the planets and funda- 

 mental stars, together with other stars, which, in the 

 annual catalogue for 1883, number 1,550. The total 

 number of transits observed was 5,213, and of circle- 

 observations, 5,049, — a larger number of meridian 

 observations than usual. But what is of more in- 

 terest, the reductions of these observations are main- 

 tained in a state of forwardness unknown in national 

 observatories generally. The computations on certain 

 stages of the reductions of the meridian-work were 

 reported to be well advanced on all observations up to 

 the middle of May, 1884. It is worthy of note here, 

 that the mean correction of the ' Nautical almanac ' 

 positions of the moon in right ascension turns out 

 to be no larger than — 0*.03 for the year 1883. This 

 interesting concordance of theory and observation is 

 due to the adoption in the 'Nautical almanac' of 

 Professor Newcomb's corrections to the ' Tables de 

 la lune ' of Hansen, which are the same as those 

 employed in the construction of the 'American 

 ephemeris.' 



The observations with the altazimuth have been 

 restricted to the period from the last quarter of the 

 moon to the first quarter in each lunation; it being 

 considered, that, from the first quarter to the last, the 

 observations of the moon on the meridian will be 

 obtained in sufficient abundance. The astronomer 

 royal regards it as evidence of the great value of the 

 altazimuth, that, during the former period, nineteen 

 observations of the moon were secured with it at 

 times when the moon's meridian-passage took place 

 within three hours of the sun, and when observation 

 with the transit circle was thus impracticable. 



With the equatorially mounted refracting tele- 

 scopes, only the usual observations were conducted ; 

 but, with the spectroscope, results of much importance 

 and interest were reached. " For the determination 

 of motions of stars in the line of sight, four hundred 

 and twelve measures have been made of the dis- 

 placement of the .Fline in the spectra of forty-eight 

 stars, ninety-one measures of the b lines in nineteen 

 stars, and two measures of the D lines in one star, 

 besides measures of the displacements of the b and 

 F lines in the spectra of the east and west limbs of 

 Jupiter, and in the spectra of Venus and Mars. . . . 

 Some preliminary measures have also been made of 

 the F line in the spectrum of the Orion nebula. 

 The progressive change in the motion of Sirius from 

 recession to approach, alluded to in the last two re- 

 ports, is fully confirmed by numerous observations 

 since last autumn, and a change of the same charac- 

 ter is indicated in the case of Procyon." 



With regard to solar photography, undertaken with 

 the view to determine the amount of spotted area, it 

 is interesting to note that the heliograph, which up to 

 the present time has given pictures of four inches 

 diameter only, has been modified so as to take eight- 

 inch pictures, as was suggested two years ago by the 

 solar-physics committee. The photographs taken in 



India under the auspices of the same committee are 

 now sent to Greenwich for reduction, thus resulting 

 in a considerable increase in the number of days for 

 which photographs are available. In 1883, for ex- 

 ample, photographs on 215 days at Greenwich are 

 supplemented by those on 125 days of India, giving 

 a total of 340. In 1882, to 201 days at Greenwich 

 were added 142 India, thus leaving only 22 days 

 without photographs in the entire year. In the 

 photographic branch of the observatory-work there 

 has been much pressure " during the long-continued 

 maximum of sun-spots, the work of measuring the 

 photographs having been somewhat further increased 

 by the adoption of large-scale photographs of the 

 sun." 



The acquisition of the Lassell equatorial, and the 

 uses to which the astronomer royal proposed putting 

 it, were mentioned in the report of the previous year. 

 A new dome for this telescope, thirty feet in diameter, 

 and covered with papier-mache on a framework of 

 iron, was completed by the Messrs. T. Cooke & Sons 

 of York in March last ; and the building is now about 

 complete in all its details. The instrument itself has 

 been generally cleaned and repaired. The mirror is 

 in very good condition as regards polish, and the 

 definition on stars is satisfactory. 



The magnetic and meteorological observations have 

 been continued with the same regularity as in pre- 

 vious years. The mean temperature of 1883 was 

 49°. 3, being 0°.4 lower than the average. The highest 

 air-temperature was 85°. 1, on Aug. 21 ; and the lowest, 

 20°. 6, on March 24. The mean daily motion of the 

 air during the year was 291 miles, which is 12 miles 

 more than the average. The number of hours of 

 bright sunshine during 1883 was 1,241, being about 

 30 hours above the average of the six preceding 

 years. Mr. Christie informs us that no definite con- 

 nection was noticed between magnetic or electric 

 disturbances and the phenomena of the remarkable 

 sunsets of the past winter. 



THE UNITED-STATES GEOLOGICAL 

 SURVEY. 



Annual reports of the United- States geological survey 

 to the secretary of the interior, ii., iii. J. W. Pow- 

 ell, director. Washington, Government, 1882- 

 83. 55+ 588 p., 32. fig., 62 pi.; 18+ 564 p., 56 fig., 



35 + 32 pi. 8°. 



It has often been remarked that the problems 

 of geology are expressed in far simpler terms 

 in America than in Europe, the birthplace of 

 the science. It is hard to say whether it would 

 have been better for geology if it had been 

 born in a less adverse environment. Perhaps 

 it might have developed more rapidly, but prob- 

 ably not so healthily. Perhaps the very diffi- 

 culties of the problems of geology in Europe — 

 the conflicts of the schools through which the 

 young science passed — have tended to invig- 



