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Roman Technics and Industry in Early Germany

A Commercial and Technical as well as a Political Conquest

Agricultural Fertilizer

Biochemical Systems

And Their Function in the Development of the Organism

By W. Bechterew

Oxy-Acetylene Welding

How to Make a Complete Oxy-Acetylene Welding Outfit

By A. H. Waychoff

A Physiological Puzzle

Hypnosis of Animals and Insects and Comparisons With Human Beings

Reinforced Concrete Aqueduct

Glass Surfaced Roads

Color Photography

A Brief Review of Its History and Details of Development

By M. C. Rypinski

German Plants in Belgium

The Spinning of a Web

A Wonderful Bit of Engineering and Technical Skill

By Frank Cuttriss

“Standardizing” the Art of Voice Production

The Fundamental Underlying Principle of Developing the Vocal Muscles

By Floyd S. Muckey

Concentration and Co-operation in Science

An Insoluble Seal for Letters

By Delta

The Chemistry of the Incandescent Gas Mantle

The Materials Employed and the Steps Taken in its Improvement

By H. S. Miner

Industrial uses of Hydrofluoric Acid

The Artificial Production of Pearls

By F. E. Chidester


The Gas from Blast Furnaces—IV

Its Cleaning and Utilization

By J. E. Johnson

Mathematics and Artillery Science

Light, Power and Irrigation in California

New Books, Etc.


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