Chapter XV. The Energy of the Sun, and How Heat is Measured 208-216

Fuel Economy. Direct Conversion. The Measurement of Heat. Caloric. Material Theory. Heat Transmitted in Three Ways. Conduction. Convection. Radiation.

Glossary 217

LIST OF ILLUSTRATIONS

FIG. PAGE

1. Undershot Wheel 13 2. Overshot Wheel 14 3. Primitive Boiler 24 4. Return Tubular Boiler 25 5. Cornish, or Scotch Boiler 25 6. Water Tube Boiler. End view 27 7. Water Tube Boiler. Side view 29 8. The Original Engine 33 9. Horizontal Section of Tube 33 10. Steam-Atmospheric Engine 35 11. Simple Valve Motion. First position 38 12. Simple Valve Motion. Second position 38 13. Effective pressure in a Cylinder 42 14. Indicating pressure line 44 15. Indicating the Engine 45 16. Compound Engine 53 16a. Relative Piston Pressures 54 17. Changing Pressure into Velocity 55 18. Reaction against Air 56 19. Reaction against Surface 56 20. Turbine. Straight Blades 57 21. Curved Blades 58 22. Compound Turbine 58 23. Two-Cycle Engine. First position 71 24. Two-Cycle Engine. Second position 73 25. Two-Cycle Engine. Third position 73 26. Four-Cycle Engine. First position 75 27. Four-Cycle Engine. Second position 75 28. Four-Cycle Engine. Third position 76 29. Four-Cycle Engine. Fourth position 76 30. Valve Grinding 81 31. Carbureter 87 32. Carbureter 95 33. Surface Carbureter 98 34. Dry Cell 108 35. Series Connection 109 36. Multiple, or Parallel Connection 110 37. Series-Multiple Connection 111 38. Circuit Testing 113 39. Make and Break, with Battery 114 40. Make and Break, with Magneto 117 41. Magneto Spark Plug 119 42. Illustrating Alternating Current 122 43. Alternating Current. Second position 122 44. Alternating Current. Third position 123 45. Alternating Current. Fourth position 124 46. Making the Circuit 125 47. The Dynamo 126 48. The Magneto 126 49. Current by Induction 128 50. Induction Coil 129 51. Typical Induction Coil 130 52. Contact Maker 131 53. Typical Circuiting, Jump spark Ignition 132 54. Metallic Core, Induction Coil 133 55. Condenser 134 56. Vibrator Coil and Connections 135 57. The Distributer 137 58. Circuiting with Distributer 138 59. Illustrating the Unit of Time 142 60. The Proney Brake 143 61. Double Eccentric Reversing Gear 146 62. Reversing Gear, Neutral 146 63. Reversing Gear, Reversed 147 64. Single Eccentric Reversing Gear 147 65. Balanced Slide Valve 148 66. Valve Chest. Double Port Exhaust 149 67. Balanced Throttle-Valve 150 68. Watt's Governor 151 69. The Original Injector 152 70. Injector with movable Combining Tube 154 71. Feed Water Heater 156 72. Check Valve 158 73. Gate Valve 159 74. Globe Valve 160 75. Corliss Valve 162 76. Corliss Valve-operating Mechanism 163 77. Angle Valve 164 78. Rotary-Valve 165 79. Two-way Rotary 165 80. Rotary Type 166 81. Two-Way Rotary Type 166 82. Butterfly Throttle 167 83. Angle Throttle 167 84. Slide Throttle 168 85. Two-slide Throttle 168 86. Blow-off Valve 169 87. Safety Pop Valve 170 88. Heart Shaped 173 89. Elliptic 173 90. Double Elliptic 173 91. Single Wiper 174 92. Double Wiper 174 93. Tilting Cam 174 94. Cam Sector 175 95. Grooved Cam 175 96. Reciprocating Motion 175 97. Pivoted Follower for Cam 176 98. Eccentric 177 99. Eccentric Cam 177 100. Triangularly-formed Eccentric 178 101. Rack and Pinion 180 102. Rack Motion 180 103. Plain Mangle Rack 181 104. Mangle Rack Motion 181 105. Alternate Circular Motion 181 106. Controlling Pinion for Mangle Rack 182 107. Illustrating Crank-pin Movement 183 108. The Dead Center 184 109. Crank Motion Substitute 184 110. Mangle Wheel 185 111. Quick Return Motion 186 112. Accelerated Circular Motion 187 113. Quick Return Gearing 188 114. Scroll Gearing 189 115. Simple Rotary Engine 196 116. Double-feed Rotary Engine 198 117. Adhesion Motor 200

INTRODUCTORY

The motor is the great dominating factor in the world of industry. Every wheel and spindle; every shaft and loom, and every piece of mechanism which has motion, derives it from some sort of motor.

The term _motor_ has a wider significance than any other word. A steam engine is a motor, and so, also, is a dynamo, a water wheel or a wind mill.

It would be just as descriptive to call a wind mill a wind _motor_, or a steam engine a steam _motor_, as to adhere to the old terms; and, on the other hand, since it would be out of place to call a dynamo or a wind mill an engine, the word _motor_ seems best adapted to express the meaning of every type of mechanism which transforms energy into motion.

In considering the subject I shall proceed on the theory that the boy knows nothing whatsoever of the subject, nor the terms used to designate the various phases, subjects and elements. It must be elementary in its character, and wholly devoid of technical terms or sentences.

While it is necessary to give information in a book of this character, on the methods for figuring out power, it must be done without resorting to the formulas usually employed in engineering works, as they are of such a nature that the boy must have some knowledge of the higher mathematics to follow out the calculations employed.

Indeed, every phase should be brought within the mental view of the boy, and to do this may occasionally necessitate what might appear to be long drawn out explanations, all of which, it is hoped, will be the means of more clearly presenting the subject.

The opening chapters, which treat of the fundamentals, will be as nearly complete as possible, and thus lay a foundation for the work we shall be called upon to perform, when we treat of the structures of the different parts and devices in the various types of motors.

The object is to explain power in its various phases, how derived, and the manner in which advantage is taken of the elements, and substances with which we are brought into contact. The reasons for each step are plainly set forth with the view of teaching the boy what power means, rather than to instruct him how to make some particular part of the machinery.

_The Inquisitive Trait._--My experience has impressed me with the universality of one trait in boys, namely, that of inquisitiveness. Put a machine before a boy and allow him to dissect it, and his curiosity will prompt him to question the motive for the particular construction of each part of its make-up.

_The Reasons for Doing Things._--He is interested in knowing the reason why. Every boy has the spirit of the true investigator,--that quality which seeks to go behind or delve down deeply. This is a natural instinct.

_The Mystery of Mechanism._--If this taste is gratified, and he thereby learns the mystery of the machine, what a wonderful world is opened to him! The value of the lesson will depend, in a large measure, on the things which he has found out for himself. It is that which counts, because he never forgets that which he has dug out and discovered.

_Curiosity Which Prompts Investigation._--I recall a farmer's boy whose curiosity led him to investigate the binding mechanism of a reaper. It was a marvel to him, as it has been to many others. He studied it day after day, and finally, unaided mastered the art. That was something which could not be taken away from him.

It was a pleasure to hear him explain its operation to a group of boys, and men, too, in which he used the knot itself to explain how the various fingers and levers coöperated to perform their functions. It was an open book to him, but there was not one in the group of listeners who could repeat the explanation.

_The Sum of Knowledge._--It is the self-taught boy who becomes the expert. The great inventors did not depend on explanations. A book of this character has a field of usefulness if it merely sets forth, as far as possible, the sum of useful knowledge which has been gained by others, so as to enable the boy to go forward from that point, and thus gain immensely in time.

There is so much that has been developed in the past, with reference to the properties of matter, or concerning the utility of movements, and facts in the realm of weights, measures, and values of elements which he must deal with, that, as he studies the mechanical problems, the book becomes a sort of cyclopedia, more than a work designed to guide him in the building of special engines or motors.

The Author.

MOTORS