BC, forty-seven of them produce two notes with minor third intervals while sixteen produce two notes with major third intervals. Tung oil: The tung oil tree originates in southern China and was cultivated there for tung oil, but the date of cultivation remains unknown. During the Song Dynasty, tung oil was used for waterproofing on ships. Tung oil is etymologically derived from the Chinese tongyou. The earliest references for Chinese use of tung oil is in the writings of Confucius around 500 to 400 BC The Chinese have used tung oil, also known as China wood oil, for at least 2500 years for building waterproof boats and paper parasols, wood finishing, wood waterproofing, caulking, inks and paints. W Well drilling: The earliest record of well drilling dates from 347 AD in China. Petroleum was used in ancient China for "lighting, as a lubricant for cart axles and the bearings of water-powered drop hammers, as a source of carbon for inksticks, and as a medical remedy for sores on humans and mange in animals." In ancient China, deep well drilling machines were in the forefront of brine well production by the 1st century BC. The ancient Chinese developed advanced sinking wells and were the first civilization to use a well-drilling machine and to use bamboo well casings to keep the holes open. Well-field system: The well-field system was a Chinese land distribution method existing between the ninth century BC (late Western Zhou dynasty) to around the end of the Warring States period. Its name comes from Chinese character 井 (jǐng), which means 'well' and looks like the # symbol; this character represents the theoretical appearance of land division: a square area of land was divided into nine identically-sized sections; the eight outer sections (私田; sītián) were privately cultivated by serfs and the center section (公田; gōngtián) was communally cultivated on behalf of the landowning aristocrat. Wheat gluten: The earliest description of wheat gluten comes from 6th century China. It was widely consumed by the Chinese as a substitute for meat, especially among adherents of Buddhism. The oldest reference to wheat gluten appears in the Qimin Yaoshu, a Chinese agricultural encyclopedia written by Jia Sixie in 535. The encyclopedia mentions noodles prepared from wheat gluten called bo duo. Wheat gluten was known as mian jin by the Song dynasty (960–1279). Wheelbarrow: The earliest wheelbarrows with archaeological evidence in the form of a