Definition: also called a monstrance, this is a ceremonial shrine in which the Blessed Sacrament or host used in communion is publicly exposed; it may be of gold, silver, brass, or copper gilt, and the most appropriate form is that of the sun emitting its rays to all sides. The oldest artifact of early European occupation in Wisconsin today is a soleil ostensorium wrought in silver and presented by trader Nicolas Perrot to the Jesuit mission at Green Bay in 1686, usually called "Perrot's Ostensorium."
[Source: Catholic Encyclopedia; Wisconsin: comprising sketches of counties, towns, events, institutions, and persons, arranged in cyclopedic form, ed. by Ex-Gov. Geo. W. Peck (Madison, Wis., Western Historical Association, 1906).