meant to any ploughboy in old England that it was April because during the first half of April the sun traverses the last half of Aries, the constellation of the Ram. Chaucer, by the way, wrote a book to teach "litel Lewis" his son, "to knowe every time of the day by the light of the sonne, and every time of the night by the starres fixed."
To locate a planet in modern days one has only to look up its position in the almanac or on a monthly sky map and then find it similarly located in the same constellation in the sky. The Monthly Evening Sky Map, an eight page journal for the amateur published by Leon Barritt, 150 Nassau St., New York, contains not only a map of the sky for every month, but also current astronomical news. With such aid, after becoming familiar with the belt of zodiacal constellations—which are easily learned by the following verse, it is not difficult to find the nearest planets.
"The Ram, the Bull, the Heavenly Twins
And next the Crab, the Lion shines
The Virgin and the Scales.
The Scorpion, the Archer and He-goat,
The Man that holds the Watering-pot,
The Fish with glittering tails."
Both Venus and Jupiter are brighter than first magnitude stars and will be recognized with but little difficulty. Mars and Saturn are as bright as first magnitude stars, although Saturn is not so easy to find unless its location is definitely known. Venus is a very white star, Jupiter a bright yellow, Saturn a pale orange, and Mars a fiery red. Mars wanders farther south than any other planet seen in the evening skies. Mercury may sometimes be seen after sunset in the spring or before sunrise in the fall, but only for a few days at a time and hence will seldom be seen by one who does not know just when, as well as where, to look for it. Uranus and Neptune are too far away and the planetoids too small to be of much interest to amateurs.
If examined with a glass the planets will show a bright round disk while a star is no more than a point of light. Mercury and Venus show phases just as our moon for their orbits lie between the earth and the sun. Venus is particularly beautiful as a crescent and is best seen in the west near the setting sun. Jupiter ranks second in popularity for even a field-glass discloses his round shining face and four of his principal moons.
THE PLANETOIDS
THE MINIATURE WORLDS OF THE SOLAR SYSTEM
Between Mars and Jupiter lies an immense lane of over 300,000,000 miles. This lane had been considered vacant until a century and a quarter ago, and since it was an exception to the general law of planetary distances, it had long been of interest to astronomers. Mercury, Venus, Earth and Mars are distant 35,750,000; 66,750,000; 92,500,000 and 141,000,000 miles, respectively, from the sun; then came this wide vacancy, with the order for the distances between the planets again resumed beyond Jupiter. When the great Kepler suggested that there must be an invisible planet revolving in this gap, many thought that the idea was only a dream of a great mind, for a planet so close would have been discovered long ago. Yet the suggestion was often considered, for the space had been to astronomers as a false note is to a musician, and they knew that if there were only a planet circling here, the spaces between every world would "increase with regularity in proceeding outward from the sun" and the solar kingdom would then be laid out in perfect harmony. The matter was left at this stage for many years, indeed it was not until 200 years after the suggestion was made that astronomers banded together, divided up the zodiac into twenty-four parts and, distributing them among an equal number of observers, began a systematic search. It is quite likely that during the 200 years previous to 1801, when the search began, not an astronomer lived but who had at some time wished to participate in such a search. Astronomers were, however, so few, the heavens so wide and life so short, that there was more than a load already on each of those earnest workers among the star fields.
Why is it, by the way, that more people are not curious about the sky? It sometimes happens that those who have stars for a hobby, a rocking-horse Pegasus, unexpectedly find themselves transported by the Winged Horse to regions above. Thus, Piazzi, at Palermo on the island of Sicily, happened across the first of the little planets, or "planetoids," quite by accident, delighting not only himself but every scientist in the world, for order was now established in the solar system. Although this newly discovered planet was so tiny that its whole surface was no more than equal to the area of the United States, the very fact of its existence in what had seemed a wasted space, probably gave as much satisfaction as the discovery of Uranus ten years before. At the request of Piazzi, the new planet was named Ceres after the tutelary Goddess of Sicily, and
