The firing shrinkage of a clay is usually about the same as the drying shrinkage. Total shrinkage will usually be about 8-12%. The next stage that happens during the firing process is vitrification. This is the hardening, tightening and finally the partial glassification of the clay. Vitrification results from fusions or melting of the various components of the clay.
Middlesboro is served by the Middlesboro-Bell County Airport, which is a single runway, general aviation airport and is the second oldest airport still in use in Kentucky, ranking behind Bowman Field in Louisville.. The airport was established in 1944, however, the first recorded flight into the city was in 1912.
Not to be confused with Middletown, Kentucky, near Louisville. Middlesboro (local /ËmÉªdÉlzbÉËrÉ/) is a home rule-class city in Bell County, Kentucky, United States. The population was 10,334 at the 2010 U.S. census, while its micropolitan area had a population of 69,060. It is located 1 mile west of the Cumberland Gap and is the largest city in southeastern Kentucky.