Siemens Telegraph Insulator
By Caleb Thimell; posted November 25, 2011
View Original: Click to zoom, then click to magnify (2816 x 2112) 1572KB
|
Here's a look at the porcelain threads. The coiled cemented insert (like ramshorn) is gone. |
|
|
Here's a look at the porcelain threads. The coiled cemented insert (like ramshorn) is gone. |