A small collection of vegetable ivory thimble holders, some with Stanhope viewers, and other sewing items with Stanhope Viewers. Vegetable ivory kernels are picked up from the ground after the ripe fruit has detached from the tree and forest animals have taken care of the pericarp, or harvested when ripe and the pericarp manually removed. As the nut shrinks when it hardens a small hollow cavity can form in the centre. It is often not possible to know whether the inside of the nut will have a small cavity in the centre until it is cut into. Therefore, when carving, it is common to either incorporate the hole or cavity into carvings or not carve deep enough to reach a potential cavity. For many years people have been using vegetable ivory to make a variety of items. The tagua nut from South America was brought to England in small quantities during the 1820s and 1830s. Toys, umbrella handles, and carvings were made from the nuts. A few tons made it to Germany in the late 1850s. By 1862 button factories were being established in France and England, in Leeds, Massachusetts in 1864, in Canada in 1870, and by the German-American Button Company Rochester, New York in the early 1880s. By 1887, it was recorded that two or three million nuts were used each year by the factories in London and Birmingham, England. During the Victorian age many items were crafted by hand-carving or turning on an ornamental or conventional lathe; included were thimbles and thimble cases with threaded lids, needle cases with threaded lids, tape measures with spindles, ear rings, dice, and rings. Most of these were highly ornamented. All these are C19th examples. Charles, the third earl of Stanhope gave his name to the device, a noted 18th-century scientist, who created the lens; the rod of glass is convex on one side and flat on the other, magnifying the object beneath. The image is dependent upon microphotography — reducing the printed image to a very small size — and this was pioneered by Englishman John Benjamin Dancer. It was Frenchman René Dagron who saw the commercial possibilities of combining the Stanhope lens with microphotography. He developed the device that allowed for the easy viewing of the tiny photos. Dagron aggressively marketed Stanhopes to a 19th-century public that delighted in visual tricks and the surprises of new technologies.