| Original Message: Invalid Generalization ! |
|---|
|
Dear Gabriel, Your generalization is not based on fact, and actually is wholly untrue. What you are discussing is not an issue of age, but rather of manufacture. Taking the topic of wound beadmaking, there are two primary types: 1) those made at a furnace; and 2) those made at a lamp or torch. From antiquity through present times, a furnace-wound bead was and is typically made on an iron mandrel—often a large-diameter mandrel. The iron leaves behind a black fire-scale, when the bead is knocked-off of it. This black fire-scale with be in an ancient bead as well as a new bead made in the same manner. So, a black perforation deposit is NOT an indication of antiquity. It is true that in the past, before lampworking was developed, most wound beads were made at a furnace, and we should expect these beads to have black deposits in their perforations (unless this were removed). When furnace-wound beads are made in certain industries (such as China in the 19th C.), the makers may take the approach of using a mandrel-release compound (as explained below)—so not all furnace-wound beads were made on iron mandrels, and therefore will not have a black deposit. When wound beads are made at a lamp or torch (the "lamp" was developed at Venice several 100s of years ago; whereas the torch is used by current beadmakers), it is typical for the workers to use a separating compound (sometimes called "mandrel release" or "bead release") that allows the bead to be cooled on the mandrel, and removed later, after annealing. At Venice, in the late 19th or early 20th C. they introduced the new approach of forgoing mandrel release, cooling and annealing the bead on the "wire" used, and dissolving the "wire" with acid. Consequently, modern Venetian beads typically have very small perforations, and no deposit in them (from a mandrel release). Earlier Venetian beads tend to have larger perforations, and no deposit within them. How these beads were removed from their mandrels has not been explained, but the typical appearance is of a smooth-sided shaft. It is also typically straight-sided, and not tapered (as are many ancient beads). Anyway, there are quite a few variables that must be juggled and dealt with. About fifteen or twenty years ago, Elizabeth Harris made an analysis of the characteristics of perforations from different industries that made wound beads around the world. Peter Francis did a similar survey. I recall that they did not entirely agree, about details such as "colors of release compound" and such. The point is, the situation is much too complicated to be handled by the simple generalization you offered. What you wrote mainly pertains to type manufacture, NOT to time of manufacture. Jamey All rights reserved by Bead Collector Network and its users |
|
|