



ASTRONOMY AND METEOROLOGY. 323 



the confusion arising from the local condensation of its watery parti- 

 cles. There can be no doubt that Schroter was mistaken in thinking 

 that accumulations of vapor would appear as dark spots upon a plan- 

 etary disc ; the old Hanoverian confounded the interior effect, or that 

 produced upon an eye beneath them, which, of course, would be one 

 of gloom from intercepted light, with the exterior aspect to a distant 

 observer, which would be eminently luminous, few bodies reflecting a 

 more intense white light than the upper surface of a densely com- 

 pacted cloud ; and hence those regions of the earth which are some- 

 times for months together overshadowed by a cloudy pall, must, to an 

 external eye, present a peculiarly white and luminous appearance ; 

 while, for a like reason, the edges of the disc, where oblique vision 

 would render vapor more perceptible, would possess not only the rud- 

 dier, as before suggested, but the more vivid light. And thus it is 

 easy to see how baffling an impediment our atmospheric variations 

 must interpose in the way of any accurate comprehension and de- 

 lineation of the features of our globe, and how the configurations 

 which a distant observer would at one time congratulate himself upon 

 having satisfactorily traced, might, after a short interval, be wholly 

 defaced and obliterated, or so intermingled with the outlines of super- 

 jacent vaporous masses as to produce a degree of entanglement re- 

 quiring a long period for the extrication of anything like a reliable 

 result. 



THE PRESENCE OF AN ETHEREAL MEDIUM PERVADING SPACE. 



In a recent able communication to the Philosophical Magazine (Lon- 

 don), on the " Phenomena which may be traced to the presence of a 

 medium pervading space," by Prof. Daniel Vaughan, of Cincinnati, 

 Ohio, the author calls attention to the ultimate effects of an imped- 

 iment due to the presence of assumed ethereal fluid or medium in the 

 dark systems of remote space. In these ultimate effects he finds an 

 explanation of the temporary stars. He regards these celestial ap- 

 paritions as indicating the existence of the ethereal fluid, and as 

 manifesting the great revolutions to which this fluid leads in the con- 

 ditions of the bodies in space. 



To combat the theory adopted by Arago and others, which 

 assumes that the ephemeral exhibition of temporary stars is due to 

 the rotation of great orbs, self-luminous on one side, and dark on 

 the other, Mr. Vaughan urges that to make a partially luminous 

 sphere or spheroid display its brilliancy to the inhabitants of the earth 

 for only seventeen months, while its period of rotation has been esti- 

 mated at three hundred and nine or three hundred and eighteen 

 years, the surface of the supposed distant sphere must be nearly two 

 hundred million times as great as the part of it sending light to our 

 planet during the period of greatest brilliancy. The light, moreover, 

 must have proceeded from the verge of the invisible disc. And this 

 circumstance, taken in connection with the surprising brilliancy of 

 the star of 1572, together with the invariability of its position, will 

 compel us to ascribe to the spectral orb in question a diameter far 

 exceeding that of Neptune's orbit. Even, therefore, if stellar move- 

 ments would permit us to suppose the existence of such stupendous 

 spheres, the explanation would be applicable to one or two cases 



