1 94 Transactions. — Miscellaneous. 



provide him with that. But I will tell you, iu confidence, that although we 

 have not dared yet to put it in black and white, yet, in our discussions, we 

 have even hinted that Laplace may have been altogether wrong, and have 

 whispered many, many reasons, on modern views of energy and the 

 dynamical theory of gases, why we think so. I will tell you one. Accord- 

 ing to Laplace, the surface of the nebulous sun should go on getting faster 

 and faster as ring after ring was thrown off; but, as a matter of fact, the 

 sun's energy of rotation is only one fifty- thousandth part of that necessary 

 to throw off a rmg, and those among us who believe in the conservation of 

 energy, ask, where is that energy gone ? It is thought possible that not 

 only may bodies thus be set travelling around the central mass, but that 

 frequently the resultant velocity left in them may carry them quite away 

 from it altogether. It is suggested that possibly the comets and shooting- 

 stars which illuminate our sky may have been thrown off at the birth of 

 temporary stars or systems, and as they travel through space come acci- 

 dentally into our Solar System, and are sometimes kept within it by the 

 retarding action of an approaching planet, or by some other cause. Almost 

 certainly they were not born with the Smi and planets ; for, of all the comets 

 observed, as many go against the direction of the planets as with it, so we 

 really must consider the comets as foreign intruders, and as such treat them 

 with the contempt they deserve. But you will say millions of millions of 

 meteorites strike the earth each year ; — exactly, probably scarcely a stellar 

 collision has occurred which did not strew space with miUions of homeless 

 particles left to wander recklessly through space, until they met destruction 

 at the hands of some pitying cosmical shark, who sympathized with them 

 in their loneliness and so took them in. But if there is so much dust flying 

 about space, it must interfere seriously with our view when we look at very 

 distant objects, as muddy water is opaque if deep. Struve held manfully to 

 his opinion, based on good evidence, that distant light did suffer extinction ; 

 and does this not appear to offer a very good reason for thinking he was 

 right 7 



But other things may be said of our two wounded stars — flint and steel — 

 whom we left travelling in space. We have seen how a spark was struck off 

 which became a temporary star, a nebula or a system, according to circum- 

 stances. We also suggested that flint and steel might become a pair of vari- 

 able stars, getting more and more distant from each other. It is possible, 

 however, if their original proper motion were small, or if they had much cut 

 off them, that they may return again and form a connected pair, and add 

 another to the many twin suns akeady existing. It is suggested that 

 probably many of these became connected in this way. It is known that 

 some binaries are variable. It is possible that these stars may come into 



