1414972

Information

• Patent Grant
• 1414972

• References
• Source

• Patent Number

  1,414,972

• Date Filed

  Not available

• Date Issued

  Tuesday, May 2, 1922
  102 years ago

• CPC

  • G01J1/40 - using limit or visibility or extinction effect

• US Classifications

  • 356 - Optics: measuring and testing
  • 235 - Registers