Feb, 6, 1879] 



NATURE 



317 



fearful, and multitudes of fragments were seen to fly off 

 by ever)' one who saw the meteor. In Indiana it was 

 thought that the explosions were heard at Bloomington 

 150 miles from the nearest point of the path. In New 

 York State the sky was wholly overcast, so that of course 

 nothing was seen. But at many places the people thought 

 there was an earthquake. Was this a solid body ? As if 

 to remove this from the class of detonating into that of 

 stone-producing meteors, one single small fragment 

 three-fourths of a pound in weight, was heard to fall and 

 was picked up the next morning on the snow in Indiana. 

 A piece of this is in the Peabody Museum. 



In i860 a meteor went north-west across Georgia and 

 Tennessee and exploded, disappearing nearly over the 

 southern boundar}' of Kentucky at a height of about 

 twenty-eight miles. There was the same terrific explo- 

 sion heard, the same scattering of fragments seen. The 

 meteor was seen over all the region from Pittsburgh to 

 New Orleans, and from Savannah to St. Louis. But 

 from this meteor no stone was found, but you cannot 

 doubt for all that that it was a solid body. 



So, a few weeks ago a meteor fell in broad daylight in 

 Southern Virginia, the sound of which, over a limited 

 region, seemed like an earthquake. It, too, must have 

 been solid. 



In July, i860, some of you, I presimae, saw a meteor 

 cross from the west to the east. It came from over 

 Northern Michigan, and was seen until it had passed at 

 least 200 miles east of us, passing between us and New 

 York City at a height of a little more than forty miles. 

 One pear-shaped ball chased a second and a third across 

 the sky. People listened for the sound to come, and one 

 or two thought that they heard it but would not affirm 

 that it was sound from the meteor. I cannot doubt that 

 that too was solid. It was seen to break in two, and the 

 parts passed on one after the other for hundreds of miles. 

 To be sure no stone was found from it, and perhaps no 

 sound heard, yet that it was solid seems to me almost as 

 sure as if I had a piece of it in my hands. 



Again, going one step farther, how can we avoid calling 

 all the meteors solid which are seen to break into pieces, 

 and all those which glance, describing a curved course, 

 or a course having an angle ? The number of such cases 

 is large, and often they are very faint shooting-stars. 

 But it is doubtful whether a small gaseous mass could 

 exist permanently as a separate body in the solar system. 

 Its repulsion would keep the parts so far asunder 

 that the sun's unequal attraction would scatter the sub- 

 stance beyond all its own power of recovery. A liquid 

 would probably freeze and become solid. In any case 

 neither a gas nor a liquid could for an instant sustain the 

 resisting pressure which a meteor is subjected to in the 

 air, much less could it travel against it ten, or forty, or a 

 hundred miles. In short, every shooting-star must be a 

 solid body. 



Second. The large meteors and the small ones are seen 

 at about the same height from the earth' s surface. The 

 larger meteors may become visible a litde higher than 

 shooting-stars, though that is doubtful ; they come down 

 in general a little lower, some of them even come to the 

 ground, but that is due rather to the size of the body. 

 The air is a shield to protect us from an otherwise in- 

 tolerable bombarding. Some of the larger balls come 

 through that shield, or, at least, are not all melted before 

 their final explosion, when the fragments, their original 

 velocity all gone, fall quietly to the ground. The small 

 ones burn up altogether, or are scattered into dust. 



In the third place, the velocities of the large and small 

 meteors agree. These velocities are never very exactly 

 measured directly ; but we are sure that in general they 

 are more than two and less than forty miles per second. 

 This is true both for small and for large meteors. The 

 average velocities for each class are not widely different. 



We sometimes need a name for the small body that 



will, if it should come into the air, make a shooting-star 

 or larger fireball. We call such a body a meteoroid. 

 Now, velocities of from ten to forty miles a second imply 

 that the meteoroids are bodies that more about the sun 

 as centre, or else move through space. These velocities, 

 as well as other facts, are utterly inconsistent with a 

 permanent motion of the meteoroids about the earth, or 

 with a terrestrial origin, or with a lunar origin. 



Fourth. The motions of the large and small meteors, 

 as we see them cross the sky, have no special relations 

 to the ecliptic. If either the one or the other kind had 

 special relations to the planets in their origin or in their 

 motions we should have reason to expect them, if not 

 always, at least in general, to move across the sky away 

 from the ecliptic. But the fact is otherwise. We see 

 both small and large meteors move towards the ecliptic 

 as often as from it. Neither class seem, therefore, to 

 have any relation to the planets. 



Again, in general character the two classes are alike. 

 They have like varieties of colour, they have similar 

 luminous trains behind them ; in short, we cannot draw 

 any line dividing the stone-producing meteor from the 

 shooting star, at least in their astronomical relations. 

 We cannot say that the Iowa meteor is different from the 

 Georgia meteor of i860, on the ground that stones were 

 found in one case and not in the other ; or that the 

 meteor of December, 1876, was different from that of 

 July, i860, on the ground that one had a series of terrific 

 explosions and the other was only seen to break into 

 parts ; or that the meteor that is seen to break into parts 

 differs from one evidently solid, that burns up without 

 any appearance of explosion. They aU are astronomically 

 alike. They differ in bigness ; but this has nothing to do 

 with their motion about the sun or in space. 



When, therefore, we learn something about the origin 

 and motions of the smaller meteoroids, we can infer like 

 facts about the larger ones. I propose, then, to show 

 that shooting stars were once pieces of comets. 



( To be continued.) 



A ZOOLOGICAL LABORATORY 



pROF. ALEXANDER AGASSIZ, in his Report to the 

 ^ President and Fellows of the Harvard College Museum 

 for 1877 and 1878, to September i, gives an accoimt of 

 his new laboratory at Newport, a plan of which he has 

 been good enough to send us. This is the first report 

 which has been presented since the Museum has come 

 under the care of the President and Fellows of Harvard 

 College, and the description given by Prof. Agassiz suf- 

 ficiently indicates that the Museum is a model of its 

 kind. During the past eighteen months increased funds 

 have been placed at the disposal of the Museum, and 

 excellent use has been made of them. Not only is the 

 Museum arranged so as to make it of the greatest service 

 to students, but in such a way that the portion thrown open 

 to the public must have an excellent educational effect. 

 Everything has been done to make visitors clearly under- 

 stand what they see, and evidently this attention is appre- 

 ciated and is answering its purpose. 



The new laborator>', erected by Prof. Agassiz at his own 

 cost, and which is a model of what such a place should 

 be, is described by Prof. Agassiz as follows : — 



The new laboratory erected by me at Newport is twenty- 

 five feet by forty-five. The six windows for work are on 

 the north side, and extend from the ceiling to within 

 eighteen inches of the floor. In the spaces between the 

 windows and the corners of the building are eight work- 

 tables, three feet by fire, covered with white tiles, one 

 foot of the outer edge being covered, however, with black 

 tiles for greater facility in detecting minute animals on a 

 black background. Between the windows, movable 

 brackets with glass shelves are placed ; whUe similar 



