ASTRONOMICAL PHENOMENA AND PROGRESS. 



51 



Helena (101). 



Epoch = 1868, Sept. 13.5 Washington M. T. 

 M = 17 48' 53".0 

 r = 328 40 Cl .0) 



ft =343 85 .IV Ecliptic and mean equinox 1868.0. 

 i= 10 4 19 .5) 

 <J= 8 48 .1 

 log a = 0.410460 

 log i*. = 2.934317 

 %= 859".640 



No. 102 (for which the name of Miriam is pro- 

 posed) was discovered by Dr. 0. H. F. Peters, 

 at Hamilton College, August 24th. It was in 

 the constellation of Pisces, and had, at three 

 o'clock of that morning, 18 38' of right ascen- 

 sion, and 12 54' decimation, moving slowly to 

 the east, and equal to a star of about the llth 

 magnitude. Observations were taken by the 

 discoverer September 13th and 14th, with the 

 following result : 



Clinton M. T. (102) a (102) 8 



1868. Sept. 13, 12* 48 30' 1 14 1.93 +12 8' 50".3 

 14,13 17 23 1 13 40.13 12 3 57 .1 



Professor Watson calculated the elements of 

 this planet in the following October, and found 

 them to be : 



Minor Planet (l( 



O h 57m 228.67 

 56 42 .78 



+ 8 43' 46".4 

 + 8 35 15 .7 



0" 22 13 s . 18 3 49' 51". 3 9 

 20 53 .94 43 47 .0 1 

 20 20.66 4 9 24 .5 7 



Oct. 11, 11" 54 10 

 12, 10 53 37 



September 7th Professor Watson added an- 

 other planet to his catalogue. The following 

 were his observations : 



1868. Ann Arbor M. T. (103) a (103) S Comp. 



Sept. 7, 15" 31 m 46 

 9, 14 45 42 

 10, 9 59 59 



The planet is of the 10th magnitude. 



Planets 104, 105, and 106, successively dis- 

 covered by the indefatigable Professor Watson, 

 were thus reported on by him to the American 

 Journal of Science : 



Communicated September 14th. I have the pleas- 

 ure to send you the following observations of a new 

 planet which I discovered last night : 

 1868. Ann Arbor M. T. a. S Comp. * 



Sept. 13, 11" 35 9" Ob 20<" 25-.61 2 a 



13, 12 35 52 '0 20 23 .65 1 lO' 52".6 4 b 

 13,13 1 33 20 22.56 1 10 48 .0 2 C 

 13, 15 55 57 20 17 .38 1 11 23 .7 10 C 

 Daily motion, A o= 45" A 5=. 5'. 

 The 'planet is of the 11.5 magnitude. 

 I have yet to add that I discovered still another 

 planet on the 16th October, of which I have observed 

 the following places : 



Ann Arbor M. T. 



(105) a 



N ^ 



(105) S 



1868. Sept. 16, 16* 3 15 0" 13 m 47 8 .42 + 6 12' 4".9 



16,16 33 22 13 46.28 6 11 45 .3 



17, 10 29 16 13 10 .57 +617 .2 



Communicated October 13th. I have observed the 



following places of a new planet discovered by me on 



the 10th inst. : 



Ann Arbor M. T. 



(106) a 



1868. Oct. 10, ID" 36 m 37 s 

 11, 11 19 

 12,10 26 52 



(106) 



lh im 2K84 + 0" 31' 42".5 

 1 34.33 28 31 .0 

 59 48.72 +0 25 31 .2 

 The planet resembles a star of the 10th. magnitude. 

 t The Motion of Sirius in Space. With the 

 aid of a new spectroscope, consisting in part 



of compound prisms, which gives a dispersive 

 power equal to nearly seven prisms of 60 of 

 dense flint glass, Mr. Huggins- has been mak- 

 ing a new series of observations on heavenly 

 bodies. His conclusions with regard to Sirius 

 are specially interesting. He is of the opinion 

 that the substance in that star, which produces 

 the strong lines in the spectrum, is hydrogen ; 

 also that the aggregate result of the motions 

 of the star and the earth in space, at the time 

 the observations were made, was to degrade 

 the refrangibility of the dark line in Sirius by 

 an amount of wave length equal to 0.109 mil- 

 lionth of a millimetre. Taking the velocity of 

 light at 185,000 miles per second, and the wave 

 length of the dark line at 486.50 millionths of 

 a millimetre, the observed alteration in period 

 of the line in Sirius will indicate a motion of 

 recession, between the earth and the star, of 

 41.4 miles per second. At the time of obser- 

 vation, that part of the earth's motion which 

 was in the direction of the visual ray was equal 

 to a velocity of about twelve miles per second 

 from the star. There remains unaccounted for, 

 a motion of recession from the earth amount- 

 ing to 29.4 miles per second, which the author 

 feels entitled to attribute to Sirius. He refers 

 to the inequalities in the proper motion of Siri- 

 us, and remarks that, at the present time, the 

 proper motion of the star in declination is less 

 than its average amount by nearly the whole 

 of that part of it which is variable, which cir- 

 cumstance may show that a part of the motion 

 of the star is now in the direction of the vis- 

 ual ray. 



Observations of Nebulm. Mr. Huggins has 

 applied his new spectroscope with some suc- 

 cess to the study of a large number of nebulae. 

 About one-third of them give a spectrum of 

 bright lines. The spectrum of the great neb- 

 ula in Orion was carefully examined by sev-. 

 eral methods of comparison, with the spectra 

 of terrestrial substances. The coincidence of 

 the lines with those of hydrogen and nitrogen, 

 remained apparently perfect with an apparatus 

 in which a difference in wave length of 0.0460 

 of a millimetre would have been detected. 

 These results increase greatly the probability 

 that the lines are emitted by nitrogen and hy- 

 drogen. Mr. Huggins regards it as a question 

 of much interest whether the few lines of the 

 spectra of the nebulae represent the whole of 

 the light emitted by those bodies, or whether 

 those lines are the strongest lines of their spec- 

 tra which have succeeded in reaching the 

 earth. He supposes that, since the nebulae are 

 bodies that have a sensible diameter, and in all 

 probability present a continuous luminous sur- 

 face, no lines have been extinguished by the 

 effect of the distance of the objects from us ; 

 and he suggests that, if we had reason to be- 

 lieve that the other lines which present them- 

 selves in the spectra of nitrogen and hydrogen 

 were quenched on their way to us, we should 

 have to regard their disappearance as an indica- 

 tion of a power of extinction residing in cosmical 



