ORIGIN OF COMETS AND METEORS. 5 i 



Monthly," the theory to which my own researches have led me the 

 more so, that I find my ideas quite commonly misapprehended, inso- 

 much that objections have been urged (as by Professor Newton and 

 by my friend Professor Young) which, though, full of force in them- 

 selves, have no bearing whatsoever on my theory as it really is. 



I may say, indeed, at the outset, that I am in thorough agreement 

 with all or very nearly all which Professor Newton has urged in the 

 way of objection against the views of those who have theorized on 

 this subject on special lines, including the view (which he attributes 

 to myself) that comets and meteors have been expelled from the sun, 

 or from the giant planets. But, at the same time, I find in all those 

 theories, including even the one mistakenly attributed to myself, the 

 germs of truth. If Schiaparelli is quite mistaken in regarding comets 

 as captured meteor-flights, we yet owe to Schiaparelli the now estab- 

 lished theory, admitted by all (unless Mr. Denning can be counted as 

 an exception), that meteors are closely connected with comets, and the 

 probable theory that comets are in reality flights of meteors, though 

 their origin in our system may not be that which Schiaparelli has 

 assigned to them. Again, Tschermak is undoubtedly mistaken in sup- 

 posing that meteorites were originally expelled from the earth's in- 

 terior, yet the evidence which he has adduced to show that a certain 

 class of meteoric bodies most probably had such an origin can not be 

 lightly overlooked. In like manner when Daubree speaks of meteor- 

 ites as having had their origin in the stars, and regards all orders of 

 them as telling us of stellar interiors, he unquestionably lays himself 

 open to the objection that certain orders of meteoric bodies can not 

 possibly have had that origin, their orbits being entirely inconsistent 

 with any such supposition. Yet, in the work Daubree has done to 

 indicate the conditions under which meteorites were first formed, he 

 has as unquestionably supplied material, of which the true theory, 

 whatsoever it may be, must take account. So with the theory which 

 I have been supposed to entertain. It is manifest that bodies shot 

 forth from the sun would either return to him, or, if their velocities 

 of ejection were great enough, would pass away not only from him, 

 but from the solar system, forever. It is manifest, also, that the giant 

 planets can not now possess power to expel bodies from their interior 

 with such force as would be required for absolute rejection as distin- 

 guished from mere temporary ejection ; and certainly nothing in the 

 present condition of our earth, or in the evidence given by her crust 

 as to past volcanic action, suggests the likelihood, if even the possi- 

 bility, that during her career as a planet she has had the power of 

 rejecting matter from her interior. 



But I have mostly found that, in endeavoring to form a true gen- 

 eral theory on a subject of this kind, it is important to gather together 

 the good features of the several special theories, not merely to note 

 such weak features as become associated with them through a mis- 



