16 



KNOW^LEDGE ♦ 



[November 1, 1888. 



It seemed certain that all meteor systems were associated 

 with comets, all comets followed by trains of meteors, 

 though the origin of meteors and of comets alike, remained 

 still enshrouded in mystery. 



lieyond this, indeed, nothing had been proved. Schia- 

 parelli's guess had never been more than a guess — that 

 meteor systems originally travelling along amid the inter- 

 stellar depths had been chrawn into the solar sphere by the 

 sun's action, and that some among them which had chanced 

 to pass near enough to the giant planets to be. deprived of a 

 sufficiently large portion of their velocities had been com- 

 pelled thenceforth to travel on the closed paths recognised 

 in the Ciise of everv meteor system yet satisfactorily dealt 

 with. Nay, I think I may say, without showing undue 

 confidence in my own accuracy, that the reasoning sketched 

 in my article on the origin of comets in the y^orth American 

 Revieic sufficed to demonstrate that, whatever the real truth 

 in the matter, Sohiaparelli's idea could not j^ossibly be 

 sound. The velocities with which meteors drawn even from 

 rest towards the sun would cross the paths of the giant 

 planets, would be such (demonstrably) that those planets 

 could not possibly capture the meteor systems, as such, in 

 the way imagined by Schiaparelli. 



On the other hand, I advanced a theory whose real force, 

 in my opinion, lay then in the circumstance that it appeared 

 the only theory available ; though there was also very strong 

 positive evidence, even then, in its favour. I suggested 

 that as the sun is known to have the power of ejecting 

 bodies from his interior with velocities sufficing to carry 

 them for ever away from him, and as microscopic evidence, 

 chemical evidence, and physical evidence had combined to 

 show that some meteors were once in a condition in which 

 they could never have been save in the interior of bodies 

 like the sun, and his fellow suns the stars, some meteors 

 and meteorites have been expelled from suns, and have 

 reached our system after journeys, lasting millions of years, 

 through interstellar space. This, of course, did not account 

 for the meteoric systems associated with the giant planets, 

 as already mentioned — that is, for those systems which, as 

 they pass very near the orbits of the giant planets, had led 

 to Schiaparelli's ingenious but inadmissible theory that they 

 were originally captured by those planets in their swift rush 

 past their mighty orbs. But my theory about the ejection 

 of some meteors from suns like our own was but part of a 

 wider theory. I have long maintained, and it is now I 

 think generally admitted, that every orb in the solar system 

 has once been in a state of intense heat — in fact in a sun- 

 like state. The giant planets have more recently ceased to 

 be suns (in glory as well as heat) than the earth on which 

 we live, or her fellow terrestrial planets Venus, Mars, and 

 Mercury ; while the glowing stage of the moon's existence 

 must be set yet further back still. Now when a giant 

 planet was a sun it must have i-esembled our sun in having 

 the power of gathering its eruptive energies from time to 

 time in such energetic throes that flights of missiles woiUd 

 be ejected from its interior with enormous velocities. Sup- 

 posing these velocities much less in the case of Jupiter or 

 Saturn than in the case of the great central sun, still they 

 might well be such that the ejected masses would never 

 return to the parent planet ; for the simple reason that much 

 smaller velocities would be required to eject missiles beyond 

 Jupiter's back-drawing power, than to eject missiles beyond 

 the much mightier back-drawing power of the sun. Now 

 flights of multitudinous small missiles, ejected in mighty 

 volcanic throes from the interior of Jupiter, would account 

 perfectly for the comets and their associated meteoric 

 attendants which hang around the orbit of Jupiter. And 

 in like manner would the remarkable comet families of 

 Saturn, Uranus, and Neptune be explained. 



But we may go a step further in this dii-ection. It has 

 been shown by M. Stanislas Meunier, Tschermak, and others, 

 that among the meteors which fall from time to time on our 

 earth are some which cannot readily be explained unless 

 we regard them as having been once ejected from our earth 

 itself. Of course, the ejection of bodies from the earth to 

 considerable distances had always been regaided as among 

 possible and even probable events. Laplace and Lagrange 

 had considered the problem of such ejection in relation to 

 the theory advanced by Olbers that the asteroids may be 

 the fragments of a former planet, ejected in so mighty a 

 throe that the whole planet went to pieces in its progress. 

 And among the conclusions they deduced was this — that a 

 planet like our earth might very readily eject masses from 

 its interior with such velocities that they would travel thence- 

 forth around the sun as a centre, though with paths intersect- 

 ing for ever thereafter the orbit of the parent planet. Thus, 

 while a mass ejected from the earth with less velocity would 

 return straightway to the earth, its path necessarily inter- 

 secting her globe (since it originated from her globe) these 

 more swiftly ejected missiles would travel on paths which 

 might leave them free to travel for thousands or tens of 

 thousands of circuits around the sun, though eventually the 

 time would probably come when in crossing the earth's 

 orbit they would find the earth herself at the crossing-place, 

 and end their career by returning to the globe from which 

 they had been ejected. Ball has shown that quite a large 

 number of the meteors which fall on the earth most probably 

 had such an origin and such a career. 



Now, there is no i-eason for excepting our earth from the 

 general rule already extended from suns to giant planets. 

 If the theory of the ejection of matter from the sun's 

 interior so that thenceforth it travels meteorwise through 

 space be sound (and it is based on direct evidence), and if 

 the theory of the ejection of matter from the giant planets 

 when in the sunlike state be sound (and it serves to explain 

 the remarkable comet families of the giant planets, appa- 

 rently explicable in no other way), then we cannot but 

 admit the likelihood, or rather we must recognise the 

 certainty, that the earth also when young and sunlike must 

 have possessed similar power. The power would be less, 

 of course, being proportioned to her mass ; but her mass 

 measures also the force which has to be overcome in oi'der 

 to get meteoric matter away with such velocity that it would 

 be beyond the earth's recalling power. Thus, then, while 

 on the one hand weighty evidence tends to show that in the 

 remote past meteoric masses have been expelled from the 

 earth's interior so as to travel thenceforth ai'ound the sun 

 as their centre, a theory based on direct evidence tends to 

 show that in her youth the earth must have possessed the 

 power to eject such masses from her interior with the neces- 

 sary velocities. {To be concluded.) 



The following extract from the official report of the 

 autopsy on the body of Mr. R. A. Proctor, whicli was sent 

 to the President of the New York City Board of Health, 

 supports the opinion expressed by the Florida medical 

 officials (see page 3) and by Mr. Proctor's relatives, that 

 his death was not due to yellow fever, but that he was 

 sufiering from malufial fever, when he was exposed on the 

 wet and miserable night of his removal from the New York 

 hotel. The medical man in attendance proposed to take him 

 to the Hospital for infectious diseases at North Brother's 

 Island. But finding the night so stormy, he did not dare 

 to carry him further than a Hospital in Sixteenth Street, not 

 devoted to infectious diseases, where he was taken in at one 



