Karin

This is not my area of expertise, but I suspect that it would be 
difficult to date a textile by the spin/ply of the yarns. As I 
understand it, the introduction of spinning machinery across Europe was 
uneven even within certain regions, and that it occurred over more than 
70 years. Throughout that period local or regional machinists (to use an 
anachronistic word) would have concocted their own--meaning that if we 
could locate enough information about this or that machine yes it would 
tell us only about the output of that machine, but there's no guarantee 
that another machine somewhere else didn't produce something reasonably 
similar.

It is also likely that older machines were either re-jigged and used for 
long periods, either where they were originally installed or else sold 
and used elsewhere.

And I would imagine that spinning standards would not have been enforced 
until after about 1850, when they would have applied so widely that 
collecting such information wouldn't tell you much.

I would be pleased to be corrected, though.

Cheers!

Sarah

Sarah Lowengard
New York, NY