from that which is entertained by distinguished astronomical authorities. For instance, in connection with Sir Norman Lockyer's spectroscopic work, he has been led to frame his meteoric hypothesis in which a comet is represented as containing a cloud of isolated meteorites. For the reasons already given I am unable to assent to this view. The structure of a meteorite seems to be wholly incompatible with the supposition that it had any other origin than as a fragment of some vast mass slowly cooled.
Another distinguished authority, Professor Newton, of Yale College, to whose labours we are so largely indebted for our knowledge of shooting - stars, also considers that a link of connection between meteorites and comets has been established. Indeed, I am aware that this belief is very widely entertained. A specimen of a meteorite has been exhibited in a museum, bearing a label with the words, "a bit of a comet," On the other hand, Professor Lawrence Smith may be mentioned as one distinguished student of meteoric matters who has accepted the view which I have here adopted, namely, that meteorites have no closer connection with ordinary periodic showers or with comets, than they have with Mars, or with Jupiter, or with the sun itself.
It will be remembered that in the early part of this chapter I have insisted on the connection between comets and shooting - star showers, which has, I believe, been abundantly demonstrated. But meteorites seem to be bodies of a radically different character from those meteors which arrive in periodic showers. Meteorites are to be explained on quite different principles; their origin is to be sought in quite different sources. In fact, the only
