Prestressed Concrete
Concrete is made stronger by Compresson; steel, by tension. These opposing properties are combined to make a building material which is stronger than reinforced concrete and cheaper than steel alone...
Features
Fossil Meteorite Craters
Canadian investigators have discovered meteorite craters at least 500 million years old. Clues from aerial photographs suggest that these fossil explosion pits are fairly common
More about Bat "Radar"
A sequel to an earlier article which described the capacity of bats to locate objects by supersonic echoes. This natural sonar is now known to incorporate extraordinary refinements
Biological Oxidation
How does the living cell "burn" carbohydrates and fats? It does so by means of an intricate web of chemical reactions which have been localized in the minute intracellular particles called mitochondria...
Predatory Fungi
Plants which trap insects are familiar in the folklore of biology. Less well-known, but more important in the balance of nature, are certain molds which ensnare and consume small animals in the soil...
Early Man in Africa
In recent years the Dark Continent has yielded the bones of man-apes and the oldest known human tools. A general account of these finds, with special reference to the author's excavations at Kalambo Falls...
The Circulation of the Abyss
Unseen and still largely uncharted currents in the ocean depths are a major force in determining world climate. A new theory indicates that these currents have a surprising pattern of flow...
Filariasis
This disease gives rise to the grotesque deformities known as elephantiasis. It is caused by threadlike worms whose activities vary in a remarkable manner with night and day
Departments
50 and 100 Years Ago: July 1958
Science and the Citizen: July 1958
- Letters
Letters to the Editors, July 1958
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
