With the Editors, April 1923

Big and Fast Liners of the Future

Atoms: Their Size and Number

A New Version of the Revolving Stage Idea

Sand-Blasting the Clouds for Man-Made Weather

Bombs and Bomb Plots

Something of the History and Construction of the Terrorist's Favorite Weapon

Pompeii Uncovered

Restoring the Ancient Italian City to Its Normal Form by Careful Excavation and Extensive Reconstruction

Tiny Air Bubbles and Giant Dams

How Air Jets Protect a Great Dam Against the Destructive Fields of Ice

Curious Concrete Bridge Tests, A Rush Job in Dam Construction

Current Psychic Investigation in Europe

Statements from Well-Known Psychic Workers, Baron von Schrenck Notzing and Mme. Bisson

Our Giant ZR-1 in the Making

A Reservoir with Cathedral Architecture, An Electron Tube Amplifier Using A. C. Current for Filaments and Plates

Floating a Bridge Into Place Section by Section, Effects of Local Conditions on Radio Direction-Finding and more

Gasoline from Natural Gas

How $200,000,000 a Year is Saved from Waste, and a Billion Gallons Added to the Gasoline Supply

The Physiology of Sweating, Food for Brain Workers and more

Taking the Kinks Out of Our Rivers

How We Can, and Why We Should, Make Our Streams Better Behave Themselves

Twelve Months of Radio

Reviewing the Outstanding Features of the Remarkable Radio Year 1922

Our Army's Helicopter, Variable Surface Wings for Variable Speed Airplanes and more

Irrigation in Australia

The Murrumbidgee Project, with Storage Capacity for 200 Billion Gallons

A Key to Many Industries

The New Technique of Die-Cutting, and the Place It Holds in Our Factories

The Minstrel Frogs

A Few Details About the Source of One of Springtime's Melodies

Powerful Wrecking Derrick for the Virginian Railway, The Sources and Characteristics of the Bacteria in Decomposing Salmon and more

Where British Patents Come From

Something of the History and Present Equipment of the Patent Office in London

Powerful Steam Fire and Salvage Boat, Another Walking Tractor

Fulfilling The Washington Naval Treaty

Scrapping a Fleet of British Dreadnoughts that Fought at Jutland

Harnessing California's Waters

The Completion of the First Stage of the Pit River Power Project

Concerning the Age of the Earth

Some of the Methods of Estimate that Have Been Used, and the Results that Have Been Obtained

Something New in Tubes: The Donle Non-Interfering Detector, A Microphonic Amplifier for Crystal Detector Sets

Short-Time Tests for Long-Time Endurance

How the Testing of Metal for Fatigue Limits is Being Put Upon a Production Basis