32 ANNUAL KECOHD OF SCIENCE AND INDUSTRY. 



tance of the spot are: Herschel (1783), 8 8'; Bessel (1830), 

 8 6'; Madler (1837), 12 0'; Secchi (1857), 17 42'; Linsser 

 (1862), 20 0'; Kaiser (1802), 4 16'; Hall (1877), 5 11'. A 

 similar work lias been clone by Professor Schiaparelli at Mil- 

 an, and he finds for 1877, September 27.0, X = 6 15', Hall's 

 result for this epoch being 5 18'. Professor Hall's observa- 

 tions were of the angle of position of the spot, while Schia- 

 parelli made his own by placing the micrometer wire tan- 

 gent to the limb of the planet at the middle of the spot. A 

 series of the same kind (as yet unpublished) was made at 

 the Dudley Observatory by Professor Boss. 



Jupiter. The conclusions of Mr. Neison upon the atmos- 

 phere of Jupiter are that it may be regarded as certain that 

 it is physically impossible for Jupiter to have an atmosphere 

 of great depth, unless the temperature of the planet be sup- 

 posed to be many million times hotter than a white heat, or 

 unless the atmosphere is constituted of some substance un- 

 known to us, and widely different from substances familiar 

 to ur.. 



Saturn. In the Astronomische JVcichrichten y Mr. Marth con- 

 tinues his very complete ephemeris of the five inner satellites 

 of Saturn. He notes the desirability of observations of the 

 conjunctions of Mimas with the ends of the ring, but has 

 overlooked the fact that no satisfactory observations of these 

 phenomena have ever been made. From his own observa- 

 tions at Malta, and the experience at Washington, it is even 

 doubtful if they ever can be made. It may be worth while 

 to note in this place the times of sidereal revolution of the 

 five inner satellites adopted by Marth. They are, Mimas, 

 d. 22 h. 37 m. 8.26 s. ; JJnceladus, 1 d. 8 h. 53 m. C.86 s. ; 

 Tethys, 1 d. 21 h. 18 m. 25.96 s.; Dione, 2 d. 17 h. 41 m. 9.33 s.; 

 Jihea, 4 d. 12 h. 25 m. 11.87 s. 



M. Tisserand continues in the Comptes JRendus his re- 

 searches on the system of Saturn, and has published the mo- 

 tions of the perisaturnium of each of the five inner satellites. 

 For Mimas this motion is 349 per annum. Tisserand further 

 shows how the mass of the ring itself may be determined, as 

 well as the oblateness of the ball. For this, continued obser- 

 vations of Mimas and Titan arc necessary. 



"The appearance of the ring of Saturn was carefully ob- 

 served at Washington during the whole opposition, and it 



