how did the mastery of the lost-wax casting technique transfer from ife to benin
Benin Bronzes In tropical Africa of the continent's center, the technique of lost-wax casting was developed early, as the works from Benin show. When a king died, his successor would order that a bronze head be made of his predecessor. Approximately 170 of these sculptures exist, and the oldest date from the twelfth century.[15] The Oba, or king, monopolized the materials that were most difficult to obtain, such as gold, elephant tusks, and bronze. These kings made possible the creation of the splendid Benin bronzes; thus, the royal courts contributed substantially to the development of sub-Saharan art.[16] In 1939, heads very similar to those of the Benin Empire were discovered in Ife, the holy city of the Yoruba, which dated to the fourteenth and fifteenth centuries. This discovery supported an earlier tradition holding that it was artists from Ife who had taught Benin the techniques of bronze metalworking.[17] Recognition of the antiquity of the technology in Benin advanced when these sculptures were dated definitively to that era.[18]
Honing oil In the context of hand blade sharpening, honing oil is used on a sharpening stone to protect the stone, carry away the debris (swarf), and to more efficiently produce a keen edge on a metal blade such as a knife.[1] In a machine shop it also carries away excess heat and depending on composition, may prevent unintentional tearing and welding of the metal. Or when used with materials such as soft copper, it may have extra additives to prevent stone loading, or metal deactivators to prevent staining of copper containing alloys.[2] To achieve maximum cutting rates and abrasive life with petroleum (mineral) based machining oils when honing difficult materials like stainless steel, a higher level of surface active lubricity agents are combined with sulfur extreme pressure additives.[3] Industrial honing oil is typically available in: 5 gal pails, 55 gal drums, 275 gal and 330 gal totes, while home knife honing oils are typically available in 1 oz, 4 oz, and 12 oz. bottles.[4]