CONTENTS. 



TOOLS. 



CHAP. 



I. THB DIGGING-STICK. SPADE. SHEARS AKD SCISSORS. CHISEL 



AND ADZE. THE PLANE AND SPOKESHAVB 222 



II. THE SAW AND ITS VARIETIES 239 



III. BORING TOOLS. STRIKING TOOLS. GRASPING TOOLS . . . 249 



IV. POLISHING TOOLS. MEASURING TOOLS 263 



OPTICS. 



I. THE MISSIONS OP HISTORY. THE CAMERA OBSCURA. LONG 

 AND SHORT SIGHT. STEREOSCOPE AND PSEVDOSCOPE. 

 MULTIPLYING-GLASSES 276 



II. THE WATER-TELESCOPE. IRIS OF THE EYE. MAGIC LANTERN. 



THE SPECTROSCOPE. THE THAUMATROPE 291 



USEFUL AETS. 



I. PRIMITIVE MAN AND His NEEDS. EARTHENWARE. BALL-AND- 

 SOCKET JOINT. TOGGLE OR KNEE JOINT 308 



II. CRUSHING INSTRUMENTS. THE NUT-CRACKERS, ROLLING-MILL, 

 AND GRINDSTONE. PRESSURE OF ATMOSPHERE. SEED DIBBLES 

 AND DRILLS 320 



III. CLOTH-DRESSING. BRUSHES AND COMBS. BUTTONS, HOOKS AND 



EYES, AND CLASP 339 



IV. THE STOPPER, OR CORK. THE FILTER 360 



V. THE PRINCIPLE OF THE SPRING. THE ELASTIC SPRING. 



ACCUMULATORS. THE SPIRAL SPRING 360 



VI. SPIRAL AND KINGED TISSUES. VARIOUS SPRINGS IN NATURE 



AND ART 375 



VII. FOOD AND COMFORT 390 



VIII. DOMESTIC COMFORT 400 



IX. ARTIFICIAL WARMTH. KING AND STAPLE. THE FAN . . .412 



X. WATER, AND MEANS OF PROCURING IT 422 



XI. AEROSTATICS. WEIGHT OF AIR. EXPANSION BY HEAT . . 436 



XII. DITTO CONTINUED 447 



XIII. TELESCOPIC TUBES. DIRECT ACTION. DISTRIBUTION OF WEIGHT. 



TREE-CLIMBING. THE WHEEL 460 



XIV. PAPER AND MOULDING 472 



XV. ELECTRICITY AND GALVANISM 482 



XVI. TILLAGE. DRAINAGE. SPIRAL PRINCIPLE. CENTRIFUGAL FORCE 492 



XVII. OSCILLATION. UNITED STRENGTH. THE DOME .... 504 



ACOUSTICS. 



I. PERCUSSION. THB STRING AND REED. THE TRUMPET. EAR- 

 TRUMPET. STETHOSCOPE . 513 



