CONTENTS XI 



58. Simple Measurement .'' V. . . 151 



59. Everything Has Weight. The Balance . 154 



60. Everything Occupies Space . . . .159 



61. Density . . . . . . . .160 



62. Drawings './.... V ".:.c>; .. . -. . . 162 



63. Forces . ..- * ' '-. ... 164 



64. The Plumb-bob and the Pendulum . . . 167 



65. The Lever . . . : ... . . 168 



66. The Inclined Plane . .' . . .170 



67. The Lodestone . . . . . .174 



68. Steel Magnets . .' , -, . . . 175 



69. Weather Observations . . . . . 182 



70. How to Make Blue-print Paper . . 183 



71. Solar Heaters . . . .. . . . 184 



72. Hot-Air Engines . . . " .- . . 185 



73. Fireproofing . .. . .. - . . . 185 



74. Waterproofing . ._ : .. ;* * . . . 186 



75. Flavoring Extracts and Perfumes .. . . 187 



76. To Remove Grease Spots and Stains . . 188 



77. How to Make Soap ,.-..... . . 188 



78. Bread Making . 1 . . . . 189 



79. Alcohol for Industrial Purposes .. . . 19C 



80. The Pantagraph . . .. " . . . 191 



81. Levelling ' ,\. .. ' '. ; .' .. , . 192 



APPENDIX. 



Reference Books on Birds . . .; '. , 195 



Reference Books on Flowers . ^. ... 195 



Reference Books on Trees ' . . . .. . 195 



List of Apparatus and Materials . . . . . 196 



