Columbia subject headings:
Harvard subject headings:
Ballooning--Social aspects--Europe--History--18th century.
Enlightenment
Hot air balloons--Social aspects--Europe--History--18th century.
Revolutions--Europe--History--18th century.
Princeton subject headings:
Ballooning--Social aspects--Europe--History--18th century.
Enlightenment.
Hot air balloons--Social aspects--Europe--History--18th century.
Revolutions--Europe--History--18th century.