America's Oldest Roads
The highways of the Incas, which are in many respects more impressive than those of the Romans, are now to be explored for the light they shed on the life of the Peruvian empire
The highways of the Incas, which are in many respects more impressive than those of the Romans, are now to be explored for the light they shed on the life of the Peruvian empire
The modern scholar uses some ingenious physical and chemical methods to explore old paintings and other works of art, tell how they were made and protect them from the erosion of time
It is one of two forms of the remarkable device that amplifies electricity by the flow of electrons in a crystal. An account of its underlying principles and present state of development...
Some of the most meaningful objects in the heavens are not visible from the Northern Hemisphere. Presenting the first photographs from the new Schmidt telescope in South Africa
Death is not only the end but also a part of life. As an inherited characteristic of living things, it is a significant clue to the mechanism of genetics
To separate plutonium and the uranium from which it is made is a difficult chemical problem. Any economic nuclear power plant will have the added problem of reclaiming its partly used fuel...
An English laboratory uses the underwater photograph to count the populations of starfish et al., and to study their place in the whole society of marine organisms
Until recently curiously little was known about this lifeline of the fetus. Now physiologists, mathematicians and engineers have discovered some impressive things about its performance