366 Transactions.— Miscellaneous. 
This is a convenient one in many difficulties. Here is something we cannot 
understand. It must, therefore, be caused in some way by that mysterious 
force, elestricity—which in the near future is to produce for us, even artifi- 
cially, light, heat, motion, and every form of energy. As is the super- 
natural to one class of people, so is electricity to another, wiser in its own 
eyes—a key to unlock every dark and mysterious chamber in the universe. 
And when we consider what electricity has enabled us to do in recent times, 
we cannot wonder that it should be credited with effects for which it is not 
at all responsible. . 
I.—Tue Cosmic Dust Turory. 
But now we must pass to theories which are more plausible; and the 
first of these is that the earth has been recently passing, particularly in its : 
intertropical parts, through some meteoric region or a cloud of cosmic dust. 
But those who advance this, forget to tell us how it is that there has been 
even less than the usual number of shooting stars during the period of the 
glows. The dust in the upper air was once thought to come from outside space _ 
and to be the residuum of burnt-out meteors. Some of these erratic bodies 
rushing aimlessly through space are, from to time, caught by the gravitation 
of the earth, and then in their rapid passage towards its centre, striking the 
air, acquire such intense heat that they burst after a very brief moment of 
incandescence into vapour and are burnt out 60 miles above the level of the 
sea (Ranyard, * Knowledge”). Now, if we had been passing lately 
through such a meteoric belt as is supposed, during the numerous clear 
nights that we have had, meteors or shooting stars such as I have described 
must have been seen in considerable numbers. Asa matter of fact none, 
or next to none, have been visible. Lockyer, Ranyard, and Williams, 
nevertheless, were at first inelined to this theory—the latter gentleman 
more especially—in consequence of the results obtained through examina- 
tion and analysis of the dust gathered from melted snow; and Mr. Ellery 
stated, in an address to the Royal Society of Melbourne on 15th November, 
that there were only two admissible theories to account for the sun-glows, 
and one was that the earth was passing through a meteoric region resulting 
in refraction of the sun's rays. Mr. Ranyard says (* Knowledge," 14th 
March) that at first he could not resist the impression that the glows were 
caused by meteoric dust, though he knew well enough that in 1861 the earth 
passed directly through a comet’s tail without any such glows appearing. 
But all these gentlemen abandoned this theory subsequently. A Mr. Biggs, 
of Launceston (Tasmania), says that if we had been running through a, 
meteoric belt such as is supposed, the meteoric bodies would have been 
falling upon us at the rate of 200,000 miles a day—that celestial fireworks 
would have been astonishing, and that everything sublunary would have 
