For both weights, in simple terms, the method of making could well have been:
- lay out the upper design (name / butterfly etc) on an iron plate
- set the plate over a flame to heat the bits as needed
- pick up a gather of clear glass on the rod and form as a cylinder
- pick up coloured bits, set out on the "marver" table, by rolling and pressing the gather onto them
- add more clear glass and form into basic rounded shape
- add the upper design by pressing the top of the rounded gather on to the plate
- add another layer of clear glass
- finish to required shape
It's easy to see that the person who laid out the ADA name simply forgot to lay out the "D" backwards - it needs to be reversed in order that it shows the right way round when picked up on the main gather.
All good fun.