passing before the light of another star. But astronomers have
in recent years invented something, the "selenium-cell," which is even
more sensitive than the photographic plate, and on this the supposed
dead star registers itself as very much alive. Algol is, however,
interesting in another way. The pair of stars which we have discovered
in it are hundreds of trillions of miles away from the earth, yet we
know their masses and their distances from each other.

The Death and Birth of Stars

We have no positive knowledge of dead stars; which is not surprising
when we reflect that a dead star means an invisible star! But when we
see so many individual stars tending toward death, when we behold a vast
population of all conceivable ages, we presume that there are many
already dead. On the other hand, there is no reason to suppose that the
universe as a whole is "running down." Some writers have maintained
this, but their argument implies that we know a great deal more about
the universe than we actually do. The scientific man does not know
whether the universe is finite or infinite, temporal or eternal; and he
declines to speculate where there are no facts to guide him. He knows
only that the great gaseous nebulae promise myriads of worlds in the
future, and he concedes the possibility that new nebulae may be forming
in the ether of space.

The last, and not the least interesting, subject we have to notice is
the birth of a "new star." This is an event which astronomers now
announce every few years; and it is a far more portentous event than the
reader imagines when it is reported in his daily paper. The story is
much the same in all cases. We say that the star appeared in 1901, but
you begin to realise the magnitude of the event when you learn that the
distant "blaze" had really occurred about the time of the death of
Luther! The light of the conflagration had been speeding toward us
across space at 186,000 miles a second, yet it has taken nearly three
centuries to reach us. To be visible at all to us at that distance the
fiery outbreak must have been stupendous. If a mass of petroleum ten
times the size of the earth were suddenly fired it would not be seen at
such a distance. The new star had increased its light many hundredfold
in a few days.

There is a considerable fascination about the speculation that in such
cases we see the resurrection of a dead world, a means of renewing the
population of the universe. What