Earhart Project Research Bulletin
July, 2002
Artifact 2-6-S-45

Secrets of the Knob

Symbol #13

Analysis and photos courtesy Jeff Glickman, Photek Imaging.


This is an analysis of photomicrographs of symbol #13 on TIGHAR artifact 2-6-S-45, commonly known as “the knob.” The photos are visually degraded because of the JPEG format which is used to enable email transmission.

This analysis contains 5 images which are separately annotated. Multiple photomicrographs using multiple illumination angles were used because of the ambiguity in this symbol. Symbol #13 is heavily encrusted, and slightly damaged.


Knobref: This is symbol #13 extracted from KnobRef.jpg. The lighting used was diffuse from above. There is a strong line near the bottom. This feature combined with shadow located to the right of the top inner circle, suggest this symbol may be a "2."

Original 54:

Note 1. Concavity on left-hand edge.

Note 2. Flow from lower-right edge.

Original 55:

Note 3. Concavity with possible fracture on right-hand edge.

Note 5. Possible physical insult against symbol.

Original 56:

Note 4. Flow from upper
right edge.

The strong line visible in “knobref” appears to be unique to this one photomicrograph. The two internal circles, combined with the concavities 1 and 3, exclude all numbers except “8.”

Conclusion: The symbol features suggest TIGHAR artifact 2-6-S-45 symbol #13 most likely is an eight (“8”).


Jeff Glickman • Photek • Board Certified Forensic Examiner • Fellow, American College of Forensic Examiners • 503-949-6200

Symbols #1-11, 19 Symbol #12 Symbol #13 Symbol #14
Symbol #15 Symbol #16 Symbol #17 Symbol #18
Preliminary Letter of Opinion

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