From the November 12, 1932, issue


Welding, an abundant source of beautiful photographs, furnishes another picture for the front cover of the Science News Letter this week; but beauty was not sufficient reason for its prominence in the cover position.

The picture was taken within a welded pipe, one-fourth-mile long, tilted up a mountainside at an angle of 45 degrees. It is the penstock, or intake pipe, to Los Angeles’ San Francisquito power plant number 2.

This pipe, says the Lincoln Electric Company, which supplied the photograph, is the world’s first arch-welded penstock. It varies gradually in diameter from 7 feet near the top to 6 feet at the bottom.


When doctors write Rx for curative atmospheres or engineers design air-conditioning apparatus to turn outdoors’ frigid winter or torrid summer into an exhilarating spring-day atmosphere indoors, they may need to specify one factor at present ignored: the electrical conductivity or ionization of the air.

Everywhere about us there are minute charged particles that act as bridges for electrical currents to cross. These ions, as they are called, start out in life as atoms or molecules from which an electron has been knocked. The removed electron becomes a negative ion, and the rest of the atom or molecule has a positive electrical charge. Next in the life cycle of an ion is the coming together of some 10 positive ions, or electron-lacking molecules, to form a positive aggregation called a “light ion” to distinguish it from a “heavy ion,” which is sometimes formed by the attachment of either a positive or negative ion to a dust or water particle in the air.

From hour to hour and place to place, the ions of the air vary. They increase under the influence of X-rays, radium, ultraviolet light, high-voltage discharges, flames, red-hot substances, and even the breaking of waves on a sea beach. The radioactive matter in the soil is probably the largest factor in the ionization of the air.

In the current issue of the Journal of the Franklin Institute, Dr. Lewis R. Koller of the General Electric Company’s Research Laboratory calls attention to the possible health importance of air ionization.

Ionization may take its place alongside pressure, temperature, radiation, and humidity as an important physical factor present in the atmosphere.


Lignin, one of the chief constituents of wood, and as yet one of the most puzzling to chemists and industrialists, has been made artificially in the U.S. Forest Products Laboratory at Madison, Wis., by Drs. L.F. Hawley and E.E. Harris. This research followed pioneer work done previously by Dr. Hawley with Dr. Jan Wiertelak.

Lignin was made in sealed tubes, by heating cellulose, the most useful constituent of wood, at a temperature of 135 degrees Centigrade for periods up to 8 days in length. The artificial lignin thus obtained gave the same reactions as the natural lignin to various chemical tests.

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