_JUPITER, THE GREATEST OF KNOWN WORLDS_ 160 Jupiter compared with our globe--His swift rotation on his axis--Remarkable lack of density--The force of gravity on Jupiter--Wonderful clouds--Strange phenomena of the great belts--Brilliant display of colors--The great red spot and the many theories it has given rise to--Curious facts about the varying rates of rotation of the huge planet's surface--The theory of a hidden world in Jupiter--When Jupiter was a companion star to the sun--The miracle of world-making before our eyes--Are Jupiter's satellites habitable ?--Magnificent spectacles in the Jovian system.