Lacemaker's Water Magnifier, Blown Glass, 18th Century, Good Condition

Here is superb "lacemaker's magnifying glass" or rather Shoemaker's magnifying glass, same principle, with a high hollow foot, blown glass, a beautiful model reproduced in the Book of J.Bellangé, (Usage and prestige glass), which presents it as a shoemaker, (Grasse Museum).
Placed between the work surface and the light source, this glass bottle, filled with water (melted snow water), was used as magnifying glass to facilitate and magnify craftsman's work and reflect light to him. See demonstration in last photos.
Beautiful blowing glass, translucent, well marked pontil under high hollow foot with hemmed ring, This beautiful and rare glassware has a good size: 35cm x 16cm.
Condition, Excellent, no or very few traces of limestone inside, no flaw for this late 18th or early 19th century object, 200 years old already....
This object is for immediate purchase, payable by credit card or paypal. - eclectic - antique dealers since 1970, Siret: FR 24.430113233.
Invoice and Certificate are attached to each of our shipments.