Tungsten Lamps of High Efficiency—II
Nitrogen-Filled Lamps
Features
Fleas can Transmit Infectious Diseases
The New Berlin Aquarium
The Old Establishment Resuscitated on a New Site
The Evolution of the Modern Stereoscope
Many Forms of the Instrument have been Devised
The Puma-Jaguar Controversy
The Problem of the Geographical Distribution of Two Species
Area of Earth's Surface Visible at any Altitude
Road Models of the Office of Public Roads
From Roman Times to the Present Day
Industrial Research in America
Some Examples of the Harvests Gathered in
Variability of Nebulae
Two Unsolved Problems of Astronomy
Planetary Pertubations and the Moon's Motion
The Nieuport Monoplane
A Machine whose Success Depends on its Wing Section
Scientific Management
The Present State of the Art
The Camphor Industry in Formosa
An Important Japanese Monopoly
