Wampum
2 of the 7 encyclopedias on this shelf carry an entry for Wampum. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the American Indian name for beads made of shells, formerly used as money, or as a medium of commerce. They were also united to form a broad belt, which was worn as an ornament, and was called wampumpaque, or wampeaque. The manufacture of wampum is carried on among the Germans living in the hills of Bergen co., N. J. The interior of a wampum workshop resembles limekiln. The a floors are hidden from sight by great heaps of shells, and the rude benches covered entirely with and tools are white-flying dust as the shells are being wh ground and drilled, and suggests the application of innumerable coats of whitewash, which in fact it really is. The wampum makers purchase a cartload of conch and clam shells for 25 cents, delivered at their doors, and when a shell of sufficient thickness is selected it is broken with h chisel into cubes of about two inches in length and one-third of an inch square. This piece of shell is then securely wedged into a vise made of two pieces of wood connected with a hinge in the center. The jaws of the vise are opened and the shells inserted. Then the vise is closed tightly and held by pressure against the grindstone. In this manner, in a short time, the edges of the shell are rounded, and then the drill is brought into use. The workman sits at a three-legged table, the top of which is fashioned from the half of a log, the under side still retaining the original bark covering, and, affixing one end of the drill to play freely in a button on his jacket, he next takes up a whalebone bow, similar to the kind used by jewelers, and, giving the cord a turn about the spool on the drill, he works the bow rapidly back and forth, from right to left, till the sharp end of the drill penetrates through the cube of shell from end to end lengthwise. When a sufficient number of cubes are completed they are then smoothed and polished with emery paper and strung on wires, precisely the same as children string beads, and they are then ready for the market. The wampum that is made from the streaked, bluish parts of hard clam shells is the most beautiful and therefore more valuable, and is harder and tougher to work. The price paid for the products of this almost obsolete industry is 14 cents a running inch on the string, and the average amount of money made by these shell artisans is about $6 a day during the season.
Aiton's Encyclopedia (1910)
wom'pum, a colored bead made by our Atlantic Indians by drilling holes in pieces of the interior of the round clam or quahog. It was much prized by them as an ornament. Strings of wampum were so valuable in aboriginal eyes that they were accepted gladly in exchange for other articles, and thus became their money. An article was valued at so much wampum. These shell beads were ground to a cylindrical form by rubbing them on a stone and were pierced by a flint awl, specimens of which have been found in the shell heaps of New England . Shell money was recognized by the laws of the colonists. In early days the ferryman charged so much wampum for setting the traveler across the stream. A wampum belt presented to William Penn by the Indians on the occasion of the famous Penn treaty is preserved by the Pennsylvania Historical Society. It consists of eighteen rows of white shell beads, in all, three thousand bits. Two dark figures are formed of dark bits. The two clasp hands,-one, wearing a hat, is for Penn; the other, bareheaded, represents the Indian. See Shell ; Beads