Proctor's Astronomical Lecture*. 



every planet Inhabited now there may be millions not 

 Inhabited, yet tlio number inhabited must be many mil- 

 lions. So that we got rid of the painful thought that 

 our insignificant planet is the only one inhabited. We 

 *ot rid of the difficulty that the greater number we 

 know of are not fit lor habitation, aud we can 

 address the Creator in the language of the poet, 



God of the pranite and the rose, 



Soul of the sparrow and the bee ; 

 The mighty tide of being flows, 



Tii rough countless channels, Lord, to thee. 

 It leaps to life in grass and flowers ; 



Through every grade of being runs ; 

 \Vhile from Creation's radiant towers, 



Its glories flame in stars and suus. 



THE STAR DKPTHS. 



FIFTH LECTURE BY R, A. PROCTOR. 



TILE SEEMING CALM OF THE STAR DEPTHS COM- 

 PARED WITH THE REAL, VASTNESS OF THE 

 MOVEMENTS TAKING PLACE WITHIN THEM DIS- 

 TANCES AND DIMENSIONS OF THE STARS- 

 DOUBLE AND COLORED STARS, AND CAUSE OF 

 THE .COLOR THEORIES OF THE STELLAR UNI- 

 VERSEDISTRIBUTION OF STAR-CLOUDLETS, AND 

 NEBULAE THE LECTURER'S PREDICTION MAR- 

 VELOfS EXTENT AND COMPLEXITY OF THE SIDE- 

 REAL UNIVERSE. 



Prof. R. A. Proctor's fifth lecture, and last but one, 

 on the discoveries of astronomy, was given Jan. 

 20. at Association Hall, aud was equal if not 

 superior in scientific interest and entertainment to 

 any of the previous four. The subject treated was 

 " The Wonders of the Star Depths," and the lecturer 

 set forth in clear and at times eloquent language 

 the various hypotheses which have been put for- 

 ward in regard to the mysterious occupants of 

 space. Additional interest was created and the 

 subject more clearly explained by means of pic- 

 tures illuminated by the powerful oxyhydrogen 

 stereopticon of the Stevens Technological Institute, 

 under the skillful management of Prof. Morton. The 

 audience was very large and strictly attentive. 



THE LECTURE. 



LADIES AND GENTLEMEN : I have seen in one 

 Of the papers a question relating to a point of great in- 

 terest in the history of our earth ; that is to say, the 

 gradual change of the earth's rotation period. It, is sun- 

 posed to have been demonstrated that this effect is duo 

 to the action of tbe lid il wave, which really acts as a 

 brake, because the tidal wave travels in a direction op- 

 posite to the earth's rotation, aud the question asked is, 

 How much does the earth's rotation lose, at what rate is 

 the great terrestrial clock losing time 1 I made a rough, 

 calculation, aud I found the loss is so small is this: 

 that at the end of 2,000 years the terrestrial time would 

 be about three minutes behind what it would be if tho 

 earth were to continue tororate from this moment on- 



ward without any change three minutes In 2,000 years. 

 You will perceive, therefore, that aa that is the accumu- 

 lated loss, that the actual loss of the earth is so very 

 small that a million of years will have to elapse before 

 any really serious change in the earth's rotation perioi 

 or the length of tho day takes place. 



THE CALM OF THE STAR DEPTHS. 



If you look at the sky in a calm, clear night, such aa 

 you have in America, "when all the star* shine and the 

 immeasurable heavens break open to their higuest," tho 

 thoughtful mind is impressed with the feeling that a 

 solemn calm reigns in those infinite depths. Tuis is tha 

 idea suggested to tho poet. Nor does any other view 

 present itself to those who stuJy the first teachings of 

 astronomy. Wo know that the stellar sphere is carried 

 from east to west as the sun and moon are carried, in. 

 the period of a single day; and we kuowif we watch 

 the heavens night after night, at the same hour, 

 there is a motion from east to west taking place in, 

 the course of a year. Aud there is yet one other mo- 

 tion <by which the whoL sphere of tha heavens saems to 

 gyrate about an axis, tlio period of that gyration being 

 26,000 years. But we know quite well that these mo- 

 tious are not real, that ihev' are produced by our earth's 

 motion. It is the earth rotating on her axis in the 

 course of a day, which causes the heavens to appear 

 to turn round in that time. It is the earth travel- 

 ing around in an orbit which causes the heav- 

 ens to have a yearly motion. Aud it is 

 the earth gyrating, like a gigantic clock, in 

 that period of 2G.COO years, that causes the whole 

 sphere of the heavens to seem to gyrate in that 

 period. But so soon as we pass from those first teachings 

 of astronomy, and consider what has been taught us by 

 modern discovery, we see that where there seems 

 to be rest there is an activity compared with which all 

 the forms of life on our earth are insignificant. Every 

 one of the stars that seem so stili, is traveling through 

 space many miles in every second of t'mo. The very 

 least of these orbs some star so faint that it is only visi- 

 ble by momentary scintillations is an orb in every 

 second of whose existence there is more life and energy 

 than is sufficient for the wants of this earth for hundreds 

 of years; and the least change of those stars, whether 

 by an increase or diminution of brightness, corresponds 

 to an accession or diminution of life and energy com- 

 parable to the supply which the earth receives from our 

 sun during hundreds of years. 



In the first lecture I reminded you of the activity of 

 the sun; that that orb is tho scene of activity, of tumult 

 and energy, compared to which all the forms of uproar 

 known to us are as nothing. Every one of these stars 

 has enacted in it a similar scene. Therefore you will 

 see how utterly different is the reality from that which 

 is presented to the mind. You look at the heavens in this- 

 country of clear skies, where everything looks so far off, 

 and the stars seem so still, aud the heavens appear so 

 tranquil seeming so suggestive of calm and peace, 

 while in reality you are looking at tho most stupendous 

 scene of activity. And now let us reflect on the facts from 

 which we have learned that this is the actual condition 

 of the s:cllar heavens. In the first place, we have to 



