Before revision: Glassblowing blowpipes are long enough to keep the gather of molten glass at a safe distance from the glassblower , and rigid enough to support the weight of the glass when the pipe is held horizontally.
After revision: Glassblowing blowpipes are long enough to keep the gather of molten glass at a safe distance from the glassblower and rigid enough to support the weight of the glass when the pipe is held horizontally.