To the best of my knowledge Germantown was a brand name like Coats & Clark.

I searched around a little and came up with the link below. You can look up Germantown as well as the aniline dye process used to color the yarn. When I searched around on the internet, the hits I got were usually connected with Indian rugs.

Here is a link that might be useful: Germantown yarn

Germantown, as already suggested, was a brandname and was usually associated with worsted-weight wool. The hook size suggested in the pattern will help you determine the thread size. An 8, 9, or 10 steel hook is often used for size 10 thread (aka bedspread cotton). Larger steel hook numbers will indicate #20 or #30 thread.

Grainlady