Perched boulder, in Bronx Park and its autograph on its rock-bed, 250 Quartz, how it helps to make the pebble jewel-boxes--the geodes, 101 Quartzite, (defined), 98 Rain, what fossil rain-drops tell of ancient weather, 224 Rat, desert, 186 Reclus, on the motion of glaciers, 62; on the mountain whirlpools of stones, 141; on the severity of lake storms, 202 Reefs, coral, how the sea helps the little people build them, 225 Reptiles, with bird feet, 246 Rivers, how the Mississippi River and others were pushed about in the Ice Age, 26; how the Old Men of the Mountain helped the Ohio by turning some rivers around, 31; how they helped make New England a great manufacturing section by turning some other rivers around, 32; how they helped build the "Temple of the Winds," 33; the little boy's definition of a river system, 66; how the sea and the rivers take turn about in emptying into each other, 66; their wonderful work in the mountains, 67; the Mississippi River system, 67; how they study the work of rivers on rainy days in Boston, 68; how you can jump across the Mississippi, 69; what springs do for rivers, 69; how the springs act as regulators of river flow, 72; how rivers grow at the top, 72; why some rivers are born partly grown, 72; how most of Europe's rivers get their start, 73; why many little rivers have to jump to catch the train, 74; why all rivers flow toward the sea, 75; beautiful way in which Ruskin tells of the response of rivers to the call of the sea, 76; the human nature in rivers, 76; baby ways of baby rivers, 76; why waterfalls are found only in young streams and more often as you near the source, 76; how rivers play in the rain, 78; storm chorus of the mountain torrents, 78; where to look for hiding rivers, 78; how rivers sleep in mountain lakes and how lively they are when they wake up, 80; why rivers grow more thrifty as they grow older; how, with the help of the pebbles, they act as bankers for the farmers and the sea, 80; the machinery of rivers includes circular saws and dirt-spreaders, 82; how a river dug the Grand Canyon, 82, 88; the automatic stop in the river machinery, 83; enormous amount of soil carried by the Mississippi into the sea, 84; how rivers cut mountains in two, 85; how rivers help in mining granite, 97; how they help make hills, 117; how they combine with the boulders to help out the artists, 157; the land in which there are river beds without rivers and rivers without mouths, 162; the skeletons of dead rivers and what they tell of the past history of the desert, 166; why dying rivers multiply by two, 167; harbor engineering of the rivers and the sea, 221; how rivers made the Golden Gate of San Francisco and so made San Francisco, 223;