expansion, 9-10, 41-42.
      filtration, 77.
      freezing, 40-41.
      hard, 225.
      heat of fusion, 40.
      impurities, 76-77.
      in atmosphere, 36-38.
      in food, 75.
      in human body, 75.
      in vegetables, 75.
      influence on climate, 29, 40.
      irrigation, 193-194.
      minerals in, 70-71.
      ocean, 265.
      power, 176-180.
      precipitates, 72, 73.
      pressure, 208-211, 214-216.
      purification, 77.
      rain, 225.
      running, value of, 178-180.
      source of, 78.
      steam, 32.
      waves, 145-147.
      weight, 208-209, 215.
      wells, 195-201.
      wheels, 176-180.
      work under, 203-205.

    Water supply, and forests, 216-217.
      cost, 212-214.
      of city, 206-212, 217.

    Watt, 351.

    Waves, heat, 145-147.
      light, 145-147.
      sound, 268, 272-274.
      water, 145-147.

    Weather, bureau, 87-91.
      forecasts, 38-39, 86-88.
      relation of water to, 29, 40.

    Weather maps, 89-91.

    Wedge, and inclined plane, 166.

    Weight, of air, 86.
      of water, 208-209, 215.

    Welding, by electricity, 315.

    Wells, 195-201.
      drilled, 199.
      driven, 196-197.

    Wheel and axle, 169-171.
      cogwheels, 170.
      windlass, 169.

    Wheelbarrow as lever, 160-161.

    White light, nature of, 135.

    Wind instruments, 297-301.

    Windlass, 169.

    Windmill, 174-175, 180-182.

    Winds, 24.

    Wine, 232, 234.

    Wood, as source of charcoal, 58.
      ashes in soap making, 223.
      in paper making, 219.
      preservation, 253-254.

    Wool, bleaching, 241.
      dyeing, 245-247.

    Work, 156-186.
      and steam, 183-184.
      and water, 176-180.
      conservation, 174-175.
      formula, 157.
      machines, 157-175.
      unit of, 172-173.
      waste, 173.

    Woven designs in cloth, 249.

    Yeast, 234-236.
      wild, 235-236.

    Zinc, in galvanizing iron, 49.
      in making hydrogen, 80.
      in voltaic cell, 307-308.

PLANT LIFE AND PLANT USES

By JOHN GAYLORD COULTER, Ph.  D.

$1.20

An elementary textbook providing a foundation for the study of agriculture, domestic science, or college botany.  But it is more than a textbook on botany—­it is a book about the fundamentals of plant life and about the relations between plants and man.  It presents as fully as is desirable for required courses in high schools those large facts about plants which form the present basis of the science of botany.  Yet the treatment has in view preparation for life in general, and not preparation for any particular kind of calling.