Adapted from “The Stars” by Sir Robert S. Ball in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

The group of bodies that cluster around our sun forms a little island in the extent of infinite space. We may illustrate this by drawing a map in which we shall endeavor to show the stars placed at their proper relative distances. 

We first open the compasses one inch, and thus draw a little circle to represent the path of Earth. We are not going to put in all the planets; we take Neptune, the outermost, at once. To draw its path, I open the compasses to thirty inches, and draw a circle with that radius. That will do for our solar system, though the comets no doubt will roam beyond these limits. 

To complete our map, we ought to put in some stars. There are a hundred million to choose from, and we shall begin with the brightest. It is often called the Dog Star, but astronomers know it better as Sirius. Let us see where it is to be placed on our map. Sirius is a good deal further off than Neptune; so I try at the edge of the drawing-board; I have got a method of making a little calculation that I do not intend to trouble you with, but I can assure you that the results it leads me to are quite correct; they show me that this board is not big enough. But could a board which was big enough fit into this lecture theatre? No; in fact, the board would have to go out through the wall of the theatre, out through London. Indeed, big as London is, it would not be large enough to contain the drawing-board that I should require. It would have to stretch about twenty miles from where we are now assembled. We may therefore dismiss any hope of making a practical map of our system on this scale if Sirius is to have its proper place. 

Let us, then, take some other star. We shall naturally try with the nearest of all. It is one that we do not know in this part of the world, but those that live in the southern hemisphere are well acquainted with it. The name of this star is Alpha Centauri. Even for this star, we should require a drawing three or four miles long if the distance from the earth to the sun is to be taken as one inch. 

You see what an isolated position our sun and its planets occupy. The stars might be very troublesome neighbors if they were very much closer to our system; it is therefore well they are so far off. If they were near at hand, they would drag us into unpleasantly great heat by bringing us too close to the sun, or produce a coolness by pulling us away from the sun, which would be quite as disagreeable.

Which of these statements about Alpha Centauri is true?

Adapted from "How the Soil is Made" by Charles Darwin in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

Worms have played a more important part in the history of the world than most persons would at first suppose. In almost all humid countries they are extraordinarily numerous, and for their size possess great muscular power. In many parts of England a weight of more than ten tons (10,516 kilograms) of dry earth annually passes through their bodies and is brought to the surface on each acre of land, so that the whole superficial bed of vegetable mould passes through their bodies in the course of every few years. From the collapsing of the old burrows, the mold is in constant though slow movement, and the particles composing it are thus rubbed together. Thus the particles of earth, forming the superficial mold, are subjected to conditions eminently favorable for their decomposition and disintegration. This keeps the surface of the earth perfectly suited to the growth of an abundant array of fruits and vegetables.

Worms are poorly provided with sense-organs, for they cannot be said to see, although they can just distinguish between light and darkness; they are completely deaf, and have only a feeble power of smell; the sense of touch alone is well developed. They can, therefore, learn little about the outside world, and it is surprising that they should exhibit some skill in lining their burrows with their castings and with leaves, and in the case of some species in piling up their castings into tower-like constructions. But it is far more surprising that they should apparently exhibit some degree of intelligence instead of a mere blind, instinctive impulse, in their manner of plugging up the mouths of their burrows. They act in nearly the same manner as would a man, who had to close a cylindrical tube with different kinds of leaves, petioles, triangles of paper, etc., for they commonly seize such objects by their pointed ends. But with thin objects a certain number are drawn in by their broader ends. They do not act in the same unvarying manner in all cases, as do most of the lower animals.

Worms are characterized as all of the following in this passage EXCEPT __________.

Adapted from "Comets" by Camille Flammarion in Wonders of Earth, Sea, and Sky (1902) edited by Edward Singleton Holden.

These tailed bodies, which suddenly come to light up the heavens, were for long regarded with terror, like so many warning signs of divine wrath. Men have always thought themselves much more important than they really are in the universal order; they have had the vanity to pretend that the whole creation was made for them, while in reality the whole creation does not suspect their existence. The Earth we inhabit is only one of the smallest worlds, and therefore it can scarcely be for it alone that all the wonders of the heavens, of which the immense majority remains hidden from it, were created. In this disposition of man to see in himself the center and the end of everything, it was easy indeed to consider the steps of nature as unfolded in his favor, and if some unusual phenomenon presented itself, it was considered to be without doubt a warning from Heaven.

If these illusions had had no other result than the amelioration of the more timorous of the community one would regret these ages of ignorance; not only were these fancied warnings of no use, seeing that once the danger passed, man returned to his former state, but they also kept up among people imaginary terrors, and revived the fatal resolutions caused by the fear of the end of the world.

When one fancies the world is about to end—and this has been believed for more than a thousand years—no solicitude is felt in the work of improving this world; by the indifference or disdain into which one falls, periods of famine and general misery are induced which at certain times have overtaken our community. Why use the wealth of a world which is going to perish? Why work, be instructed, or rise in the progress of the sciences or arts? Much better to forget the world, and absorb oneself in the barren contemplation of an unknown life. It is thus that ages of ignorance weigh on man, and thrust him further and further into darkness, while Science makes known by its influence on the whole community, its great value, and the magnitude of its aim.

The author argues that in earlier centuries comets were primarily regarded as __________.