Reclaimed wood

[stumpy]

I have some reclaimed floor joists out of a 1860's era building.  They are about 3" x 11"that I'm making a table out of.  My questions is, there is a track line down the length of one side, about 2" from the edge.  It's straight as an arrow and the notched are about 1/2" long 1/8th wide and spaced about 1" apart. Does anyone know what these tracks would have been made from?  I was thinking the were pulled thru some sort of machine when they were being milled. I'd like to know cause it would add another element of the story that goes with the wood. Just to clarify, these notches are in the wood.  I plan on lightly sanding the wood so to leave the track line visible.

[Magicman]

Got a picture?

[stumpy]

Yup, here it is