1．Hot Metal 1
2．Sir Walter Raleigh 6
3．Electric Wire 10
4．Light 15
5．Flying 20
6．In a Balloon 24
7．The Nine Planets 29
8．Eclipses 34
9．Switches and Fuses 40
10．Magnets 45
11．Otto von Guericke and the Vacuum 50
12．Galileo 55
13．Pendulums 60
14．Earthquakes 66
15．Thomas Alva Edison 71
16．Some of the Gases 76
17．Some Arab Scientists 80
18．Drills and Derricks 85
19．Mineral Oil 91
20．The Soil 96
21．Irrigation 101
22．A Ship's Propeller 106
23．Faraday and his Generator 110
24．Voltage and Current 115
25．Sir Robert Watson W 120
26．The Use of Radar 125
27．Malaria 130
28．The Air Brake 136
29．The Atlantic Cable 141
30．Gravitation 146
Notes 152