Though Pauling was officially assigned to Division B upon induction into the NDRC,
he was not limited to work with propellants. Less than a month after joining the
NDRC, Pauling was already in contact with researchers outside of his division. Even
as he began work with explosives, he was analyzing other projects and departments.
On October 3, 1940, Pauling met with W.K. Lewis in New York City. There, Lewis told
him briefly of the need for an instrument capable of measuring the partial pressure
of oxygen. He explained that soldiers operating in low-oxygen environments - primarily
airplanes and submarines - had long been fearful of unchecked oxygen depletion which
could, in extreme cases, lead to loss of consciousness and death. An oxygen meter
would allow pilots and submariners to track oxygen levels within the cockpit or submarine
cabin, allowing them to adjust for dangerous decreases.
The following day, Pauling met with Wendell Latimer and Thorfin Hogness, fellow members of the NDRC. The two men, who had previously visited naval bases
on behalf of the committee, discussed the importance of the oxygen meter with Pauling,
assuring him that it would be a significant tool for victory in the war. The following
day, Pauling began mentally sketching out plans for the instrument. Before long,
he had struck on a possible design. On October 8, he sent a telegram to NDRC administrator
James Conant stating that he had a "most promising" means of determining partial pressure.
Soon after, Pauling received an unofficial order from Harris M. Chadwell, Conant's right hand man, to begin his research.
Pauling promptly wrote a short letter to Conant describing his plan for the oxygen
meter project. He began by explaining that oxygen demonstrates strong paramagnetic
properties. This paramagnetism allows oxygen atoms to be attracted to outside magnetic
fields, a tendency not exhibited by other gases in our atmosphere. By measuring the
magnetic attraction of a sample of mixed gases, one would be able to determine the
percentage of oxygen present. He believed that a torsion balance, a sensitive device
used to measure weak forces, could determine the magnetic force exerted by oxygen
in mixed gases. In addition to outlining the design principles behind his apparatus,
Pauling requested salary allocations for two of his best researchers - Reuben Wood and Sidney Weinbaum.