CONTENTS. 



PAG* 



ANOTHER WORLD DOWN HERE, .... 7 



CONCERT-BOOH ACOUSTICS, ..... 15 



ORIGIN OF SOAP, ...... 21 



OILING THE WAVES, ...... 25 



THE ACTION OP FROST IN WATER-PIPES AND ON BUILDING 



MATERIALS, ...... 30 



FIRE-CLAY AND ANTHRACITE, ..... 37 



COUNT RUMFORD'S COOKING-STOVES, .... 45 



THE " CONSUMPTION OF SMOKE," . . . 51 



THE AIR OF STOVE-HEATED ROOMS, .... 55 



VENTILATION BY OPEN FIREPLACES, . . . 60 



DOMESTIC VENTILATION, ..... 64 



THE FUEL OF THE SUN, . . . . 72 



DR. SIEMENS'S THEORY OF THE SUN, .... 99 



THE ORIGIN OF LUNAR VOLCANOES, .... 102 



NOTE ON THE DIRECT EFFECT OF SUN-SPOTS ON TERRES- 

 TRIAL CLIMATES, . . . . . 108 



THE PHILOSOPHY OF THE RADIOMETER AND ITS COSMICAL 



REVELATIONS, . . . . . 110 



ON THE SOCIAL BENEFITS OF PARAFFINE, . . . 116 



THE SOLIDITY OF THE EARTH, .... 122 



A CONTRIBUTION TO THE HISTORY OF ELECTRIC LIGHTING, 125 



THE FORMATION OF COAL, . . . . . 133 



