It is one of the principal seats of the glass industry in Indiana - plate glass, lamp chimneys, mirrors, &c., being manufactured here - and also has mineral wool factories and paper mills.
Among several picturesque old houses remaining, that known as the Six Chimneys, an Elizabethan structure, is the most striking.
The sculptured doorways, chimneys and friezes of the interior are especially fine.
In 1905 the borough ranked fifth among the cities of the United States in the manufacture of glass (plateglass, lamp chimneys and bottles), its product (valued at $1,841,308) being 2.3% of that of the whole country.
Among the many developments of the Jena Works, not the least important are the glasses made in the form of a tube, from which gas-chimneys, gauge-glasses and chemical apparatus are fashioned, specially adapted to resist sudden changes of temperature.