As Chris Stewart
discovered, there was a distinct industry emerging by the 1880's potentially inspired by Olivotti at Paris, but certainly a subject of study in the early 19th century too as noted by Anne in the same
thread. Now where to find details of the bronze medal they received?
I guess there is a certain amount of commercial spin to the 1938 date widely quoted corning were always good at PR! No doubt with the appropriate narrowing of their definition that date becomes effective but commercial viability was earlier if all these other companies were making use of the technology - even if its application was severely limited
From the Glass-Study there are several processes mentioned and reference to 'early' drawn methods, modern (preWW2) continuous thread. In Germany 1945; Centrifugal for glass wool, rotating perforated plates (Continuous fibre), Owens-Corning (Continuous fibre & Staple) , Drawing from rods (Continuous fibre). A thickness of 5 to 6 Microns being mentioned. Textile quality was produced by American methods and insulation types by all methods.
So the hunt for Olivotti can continue, with the range of products and the language used in the 1880 report it is probable that it was a firm rather than a single producer. Somewhere out there someone must know about this company and there are probably some attributed items.
(US fiber fiberglass)