Features
A Rail Wear Testing Machine
Guncotton and its Manufacture
An Account of Modern Methods
Imitation Parchment Paper
Marine Producer-Gas Power
A Comparison of Producer-Gas and Steam Equipments
A Handy Testing Chart
What to do when the, Engine Stops
Radioactivity in Relation to Geology and other Sciences
Casting a Colossal Bronze Statue
The Monument to King Victor Emmanuel II in Rome
Weekly Weather Forecasts
New Photometric Units
An Important International Agreement
Permanent Magnets of nearly Pure Copper
The Mount Wilson 60-Inch Reflector
How the Earth Looks from the Moon
Studies of Earthlight
Flowers and Insects Transformed into Metal
Revolving Balloon Sheds
A New Type of Airship Shed that has Several Advantages
Cocoons and how they are made
Why Insects Spin Them
The Duration of Life on the Earth
The Influence of Sea and Carbon Dioxide