Business: Mr. Kollsman's Number

In most air forces and most airlines, when a pilot nears his landing field he calls the ground, asks for the "Kollsman number." What he gets is the atmospheric pressure in that area, necessary to adjust his altimeter, which actually is nothing but a barometer graduated in feet of altitude.

Kollsman is the name of a shy, German-born inventor who studied mechanical engineering at the technical schools of Stuttgart and Munich, in 1923 emigrated to the U. S., found work as a truck driver's assistant, then as a mechanic for Pioneer Instrument Co., a...

Want the full story?

Subscribe Now

Subscribe
Subscribe

Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on TIME.com

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!