Pear
2 of the 7 encyclopedias on this shelf carry an entry for Pear. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a fruit tree closely related to the apple and quince. As in the case of an apple, the core is the seed pod imbedded in a fleshy receptacle which we eat. The first American pear tree is said to have been planted in the garden of Governor Endicott, Boston, in 1630. Pear culture follows the methods of the peach and the apple orchard. The pear ripens later than the apple and is less hardy. Our pear regions are restricted. Pears winterkill, are subject to drouth, and cannot endure heat. They thrive in the region extending from New England to the Great Lakes , and on the Pacific slope. Texas is the fourth in rank as a pear-producing state. The best known varieties are the English Bartlett and the American Seckel. The Kieffer is a recent favorite. Fancy pears are sent to market in crates, each pear wrapped in tissue paper. California ships immense quantities of pears, well on toward 2,000,000 cases of crated pears, several million pounds of dried, and half a million cases of canned pears annually. American pears are well known in British markets. See Apple
Collier's New Encyclopedia (1921)
the Pyrus communis. It is a shrub or small tree, 20 to 40 feet high, with the branches more or less spinescent and pendulous, the flowers in corymbose cymes, and the fruit pyriform, one or two inches long, becoming larger and sweeter in cultivation. Many hundred cultivated varieties exist. The wood of the pear is almost as hard as box, and is sometimes used as a substitute for it by wood engravers.