These were made from around 1830 at a variety of glassworks, using glass left over from the day's production.
They come in many different sizes, with silver looking flowers, colored flower petals, airbubbles, clay dolls, busts, clay pipe heads, etc etc.
They range from small in size to quite large. The big ones were likely used for door stops while the smaller ones
fall into the paperweight/ornamental catergory - after all - a 3" by 1,5" tall glass piece won't hold a door back

It is, with a few exceptions, hard to attribute these to a specific maker as they are all very similar and seldom marked,
the exception being the maker John Kilner in Wakefield who stamped the bottoms of the paperweights with "J.Kilner Wakefield"
For more detailed information I recommend the book Old English Paperweights by Robert G. Hall, ISBN-0-7643-0539-5
Most of the information above was gleaned from that book.
There are usually a few listed on eBay at any given time.