1409225

Information

• Patent Grant
• 1409225

• References
• Source

• Patent Number

  1,409,225

• Date Filed

  Not available

• Date Issued

  Tuesday, March 14, 1922
  102 years ago

• CPC

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

• US Classifications

  • 356 - Optics: measuring and testing