Page:The New International Encyclopædia 1st ed. v. 16.djvu/379

POTTER. 321 equals his smaller pieces. The Hermitage at Saint Petersburg possesses 11, including the fa- mous '"Cow," refused by the Stadtholder's wife, and the "Judgment of the Animals Over the Hunter;" others are in the museums of The Hague, Amsterdam, Paris, Berlin, Dresden, and especially in English private collections, where the largest number are to be found. Potter was also an etcher of note, simple and direct in his treatment. He left no school, and of his supposed pupils Aelbert Klomp was a precursor, and the two Camphuysens were inde- pendent contemporaries. Consult : Van West- rlieene, Paulus Potter, sa vie et ses osucres (Hague, 1867); Grattel Duplessis, Eaux-fortes de Paul Potter (Paris, 1876). POTTER, Robert B. (1829-87). An Ameri- can soldier, born in Boston. He was a son of Bishop Alonzo Potter and a brother of Bishop Henry C. Potter. He graduated at Union Col- lege, and studied law, but in 1801 withdrew from practice in order to enter the Federal Army. He was commissioned lieutenant-colonel of the Fifty- first Xew York Volunteers, led three companies at Roanoke Island, was wounded at Xewbern, fought in the second Bull Run campaign and at South Mountain, and distinguished himself by making a spirited charge at the head of his regi- ment at Antietam, where he was again wounded. He was made a brigadier-general in 186.3, com- manded a division in the KJnox"ille campaign, serveil with Grant in the Wilderness, and was a third time wounded in the assault made on Petersburg after the explosion of the mine. He was commissioned major-general of volunteers in 1803, and resigned in 1806. POTTER-BEE. A mason bee of the genus Osmia and its allies, which constructs small globular cells of earth and attaches them to the stem of a plant in much the same manner as do the potter-wasps (q.v. ) of the family Eumenids. POTTER'S CLAY. A term commonly ap- plied to any fine-grained, plastic clay which can he used in the manufacture of pottery. Clays employed for the making of pottery must have sufficient plasticity, and also burn to the proper body without warping or cracking in the firing process. In order to produce these results it is sometimes necessary to mix two or more kinds of clay together. Potter's clays are found in many localities, and also in many different geo- logical formations ; those found in the recent sur- face deposits are commonly too impure to permit their use for anrthing except the cheaper grades of ware. The higher grades of pottery are al- ways molded from a mixture of at least three kinds of clay, and in this case the raw material is sometimes freed from gritty particles by a pre- liminary washing. After mixing it is sometimes stored in damp cellars for a year or more, with the idea that its plasticity will thereby be im- proved. The value of potter's clay ranges from a few cents per ton for common earthenware clays up to $10 or $12 per ton for china clays. In the United States the lower and medium grades of potter's clays are abundant, but the demand for the higher grades is greater than the supply, and therefore lar<re quantities are annu- ally imported from Enn;land. The following are analyses of some well-known American potter's clavs : POTTER-WASP. ASALYSES OF POTTER'S CLATS 1 2 3 4 Silica 45.70 40.61 1.39 .45 .09 2.82 8.98 .35 70.26 19.23 10.03 .83 56.44 26.60 2.00 .47 .63 3.46 7.59 2.48 45.39 39.19 .43 Lime .51 .26 Alkalies .83 Water 14.01 Moisture Total 100.39 100.35 99.67 100.67 1. Washed kaolin, Webster, N. C. : used in porcelain manufacture. 2. Stoneware clay, Greentown. Ohio. 3. Yellownare cla.T, East Palestine, Ohio. 4. Florida •• ball clay." used in whiteware manulacture. The following varieties of potter's clay are commonly recognized : Kaolin ob China Clay. A white burning residual clay used in the manufacture of china. B.LL Clay. A plastic white burning clay used as an ingredient of white earthenware and porce- lain bodies, and added on account of its plasticity and bonding power. Eaethenware Clay. Any plastic clay suita- ble for common earthenware. Stoneware Clay. A plastic potter's clay which burns to a dense impervious body. The clays employed for this purpose are commonly semi-refractory. Yellowwabe Clay. A semi-refractory clay employed for making yellowware. It is not burned to a vitrified body. Retort Clay. A dense burning fire clay much used in some districts for the manufacture of stoneware. The production of potter's clay in the United States in 1901 was as follows: Kaolin, $.584,523; ball clay, $08,907; stoneware clay, $114,613. The imports in the same year were valued at $969,- 777. BiBLiOGEAPHY. Langenbeck, The Chemistry of Pottery (Easton, 189.5) ; Ries, The Clays of Xew York, their Properties and Uses," BuUetin ■ Xew York State Museum, Xo. So (Albany, 1900) ; id., "The Clays of the United States East of the Mississippi," Professional Paiiers. United States Geological Survey, Vo. 11 (Washington, 1903). See Clay ; Kaolin ; Pipe Clay ; Pottery. POTTER'S FIELD. A place for the burial of such as have neither friends nor means to provide burial for them. The name comes from Matthew xxvii. 7. See Aceldama. POTTER-WASP, Any wasp of the family Eumenidse. the species of which form globular cells of clav or sand which are attached bv a A POTTEH-tt'ASP ASD ITS NEST. small pedestal to some twig. The shape is fre- quently very beautiful, and is precisely that of certain greatly admired Indian vessels and