Swirls/Spirals;
CONVEX RIB (AKA)
• AKA:
National Glass Company (Northwood Works) (Indiana-PA, Operated: 1899-1904), Introduced: c1902
• NOTE: Gene Serbus - all of mine have the spiral twist. The 1902 catalog cut shows one with vertical ribbing but I have never seen one.
• Motifs: (Swirls/Spirals), (Opalescent, Stripes & Swirls )