Looking Ahead With the Editor, July 1929

Among Our Contributors, July 1929

From Colombian Mountains to the Sea

A Rich Hinterland of Colombia, Seeking Independence of its Old Slow Transportation System, Builds a Road to the Sea

From the Scrap-book of Science, July 1929

The Invaders of England

An Account of the Excavation of Early British Burial Places

The Marvelous Machinery of Muscle

By Learning to Understand the Physics and Chemistry of Our Muscles We May Obtain Increased Control Over Them

A Ship that Carries Trains

Neglected Mushrooms

The Common Meadow Mushroom Is Only One of Many Kinds Which We May Learn to Recognize and Eat With Safety

Tailor-Made Weather for Offices

Equipment in an Office Building in Texas Supplies Air of Proper Temperature and Humidity to All Offices

Sky Photography for Lightning

Estimating the Age of Writing

Whether a Document Is Authentic May Usually be Discovered by Analysis of the Writing. In Legal Cases Such Methods Are Often Crucial

Earth Shine

From the Moon the Earth Would Appear Many Times as Bright as the Moon Appears from the Earth. Interesting New Research on an Old Subject

The Ultra-Violet From the Sun

A Ridiculously Small Quantity of Ozone in the Atmosphere Controls the Amount of Ultra-Violet Which Reaches the Earth's Surface

Pumps Disclose Lake Nemi's Secrets

It is Safe to Fly

High Safety Factors in Construction, and Efficient Personnel, Contribute Materially to Aviation Advancement

The World's Highest Dam for Irrigation

The Stage Goes to School

All Phases of Stagecraft are Taught in New Course in Drama

Underground Arteries for Oil and Gas

Pipelines Hundreds of Miles in Length Surmount Natural Barriers Transporting Fuel to Refineries and Distant Cities

Wings of South America

Aerial Transportation Between the Continents of the Western Hemisphere Is Increasing by Leaps and Bounds

Foiling the Burglar

From Time Immemorial Man Has Tried to Protect His Worldly Goods From the Hands of the Despoiler

Plugging Knot Holes to Salvage Lumber

Banditry by Mail

Medical Fakers Fleece the American Public of Millions of Dollars Annually Through the Mails

Why not Propel Boats by Vibration?

A Study of the Vibratory Principle of Propulsion in Nature, and the Possibility of Utilizing It for Driving Water Craft

Groupings in the Aviation Industry

Status at the Time of Going to Press

Avocados--Alligator Pears

These Tropical "Fruits" May Become as Important as Oranges in Our Daily Diet When We Learn to Like Them

Walking Around Jerusalem

The Ancient Walls of the City of David and Solomon Are Being Restored

The Amateur Astronomer, July 1929