TRANSCRIBER'S NOTES Italic text is denoted by _underscores_. The oe ligature has been expanded to 'oe'. Subscripts in chemical formulas are denoted by normal numbers; for example CaC2. Obvious typographical and punctuation errors have been corrected after careful comparison with other occurrences within the text and consultation of external sources. More detail can be found at the end of the book. [Illustration: A PRIMITIVE USE OF THE ANIMAL MACHINE THAT IS STILL IN VOGUE IN MANY EUROPEAN COUNTRIES. (From the painting by J. Didier, in the _Musée du Luxembourg_, Paris.)] EVERY-DAY SCIENCE BY HENRY SMITH WILLIAMS, M.D., L.L.D. ASSISTED BY EDWARD H. WILLIAMS, M.D. VOLUME VI THE CONQUEST OF NATURE ILLUSTRATED NEW YORK AND LONDON THE GOODHUE COMPANY PUBLISHERS MDCCCCIX Copyright, 1910, by THE GOODHUE CO. _All rights reserved_ CONTENTS CHAPTER I MAN AND NATURE The Conquest of Nature, p. 4--Man's use of Nature's gifts, p. 6--Man the "tool-making animal," p. 7--Science and Civilization, p. 8--Clothing and artificially heated dwellings of primitive man, p. 10--Early domestication of animals, p. 11--Early development to the time of gunpowder, p. 12--The coming of steam and electricity, p. 15--Mechanical aids to the agriculturist, p. 19--The development of scientific agriculture, p. 20--Difficulties of the early manufacturer, p. 21--The development of modern manufacturing, p. 24--The relation of work to human development, p. 25--The decline of drudgery and the new era of labor-saving devices, p. 27. CHAPTER II HOW WORK IS DONE Primitive man's use of the lever, p. 29--The use of the lever as conceived by Archimedes, p. 21--Wheels and pulleys, p. 32--Other means of transmitting power, p. 35--Inclined planes and derricks, p. 37--The steam-scoop, p. 38--Friction, p. 39--Available sources of energy, p. 41. CHAPTER III THE ANIMAL MACHINE The oldest machine in existence, p. 43--The relation of muscle to machinery, p. 44--How muscular energy is applied, p. 44--The two types of muscles, p. 45--How the nerve-telegraph controls the muscles, p. 47--The nature of muscular action, p. 49--Applications of muscular energy, p. 52--The development of the knife and saw, p. 53--The wheel and axle, p. 55--Modified levers, p. 57--Domesticated animals, p. 59--Early application of horse-power, p. 60--The horse-power as the standard of the world's work, p. 61. CHAPTER IV THE WORK OF AIR AND WATER