At Greenwich and at some of the other foremost observatories attempts have been made directly and indirectly to determine the distance of Nova Persei. And yet this distance defies measurement. The star is so far away that we have no instruments refined enough to deal with the problem. But we know that the sudden blazing up of Nova Persei was over and done with before our great-grandfathers were born. It happened more than two hundred years ago—perhaps two thousand years ago. All this time the news was swiftly traveling earthward, traveling on and on and on, two hundred thousand miles every second of the clock, past star and nebula and system, never halting, never faltering—yet it took hundreds of years to come to us; and beyond us lie countless worlds that will not see the new star for centuries to come. Hundreds of years hence in _their_ sky will appear suddenly in the constellation of Perseus a strange star; it will increase in brightness for a few days just as it did in ours; it will fade away intermittently just as it did in ours. There is no imagination here; only sober facts. We may be allowed, in closing our narrative of this wonderful star, to make one excursion into the region of imagination. As the news of the star passes on through space, are there any beings beyond ourselves who will take record of its appearance? It has taken centuries to come to us. Did any other creatures in some far-off world lift their eyes to the stars and wonder, as we do, what all this meant? Will some mortal, like ourselves, in some remoter world, in a day yet to come, see the sight, and have the intelligence to say, “Lo! a new star?” We have room enough here for the most extravagant fancy. Perhaps there is so much room that we shall lose ourselves if we venture to stray in such directions. TELESCOPES.—A. FOWLER THE REFRACTING TELESCOPE.—The function of a telescope is twofold. First, to magnify the heavenly bodies, or, what comes to the same thing, to make them look as if they were nearer to us, so that we can see them better. Second, to collect a much greater number of rays of light than the unassisted eye alone can grasp, so that objects too dim to be otherwise perceptible are brought within our range of vision.