Victorian Air Trap Blue Satin Vase

A nice example of this type. Could be English and made by a major firm. Unusual square top with curled edges. Clear glass over blue over white. The pontil has been ground flat for stability. The raised air bubble pattern on the exterior makes it a little different to the usual air trap patterns. The blue is darker at the top and fades away at the vase bottom. Simple design but elegant in shape and white and blue is always a good contrast. I've seen the same shape in cranberry years ago - should have bid on it. Stevens & Williams? Made in the last 15 years of 19th century. Height is just under 15 cms [6 inches] and approx 10 cms wide. Glass is reasonably thick and it is heavy.