Historical Necessity: The Birth of the “Longquan Code”

In the deep mountains of Southwest Jiangxi during the 17th century, a technological revolution in timber measurement was quietly taking place. Early timber trading was extremely imprecise, initially relying on the “pile estimation” method, where prices were negotiated based on a visual assessment of a timber pile. This often led to disputes over lengths and quality [1]. Later, a weight-based system using scales was introduced, but it proved inefficient due to varying moisture levels in the wood and the sheer difficulty of weighing massive logs [1].

In 1625 (the 5th year of Tiantian), Guo Weijing, a native of Wudoujiang in Suichuan, passed the imperial examination and began his political career [2, 3]. However, his most lasting contribution to the industry was developed alongside his talented eldest daughter, Guo Mingzhu. Living in Sanxi, the heart of the timber-producing region, the father-daughter duo observed the pain points of foresters and merchants [1, 3]. They cleverly adapted the familiar “Jin, Liang, Qian, Fen” weight system into a rigorous volume measurement standard. This system, later known as the “Longquan Code” (Longquan Ma), was formalized and widely promoted during the Chongzhen period (1628–1644) [1, 4].

The emergence of the Longquan Code marked a shift from weighing wood to measuring its diameter, drastically improving trade efficiency. Statistics suggest this system remained the standard for over 300 years, spreading throughout Jiangxi and down the Yangtze River to major ports like Wuhu and Nanjing [5].

Technical Precision: A Rigorous Logic of Measurement

The Longquan Code was not a simple conversion table but a comprehensive scientific system encompassing classification, progression, and defect handling. Its core lay in converting circumference measurements into virtual “Code Units” (Ma Liang).

Classification of “Zhengmu” and “Jiaomu”

The system enforced strict quality grades. Cedar poles with a circumference of 8 inches or more were classified as “Zhengmu” (Standard Wood), while those less than 8 inches were downgraded to “Huazhao” [6]. Log lengths were also standardized; for instance, logs 6 feet or longer were considered “Zhengmu,” while shorter ones were labeled “Jiaomu” (Sub-standard Wood) [6]. This incentivized foresters to produce longer, higher-quality timber, reducing waste.

“Bao Jiao” and Length Standards

The Code introduced the “Bao Jiao” concept, which mandated specific natural lengths for various grades [6].

  • “Xiao Fen” (Small Grade): Standard length of 2 zhang 1 foot 1 inch (approx. 7.03 meters).
  • “Zhong Fen” (Medium Grade): Standard length of 2 zhang 7 feet 1 inch.
  • “Da Qian” (Large Grade): Standard length could reach up to 5 zhang 1 foot 1 inch [6]. Logs failing to meet these length requirements were settled at a 30% discount, a rule that effectively protected young forests from premature logging [1, 7].

The “Zhuan Guan” Scaling System

The progression of values in the Longquan Code functioned as a sophisticated economic lever. The base unit was the “Liang” (Taen), where 10 Qian made 1 Liang, and 10 Fen made 1 Qian [6]. In practice, for logs between 8 and 13 inches in circumference, the value increased by 5 Li for every additional inch. However, when the circumference reached the range of 2.6 to 3 feet, the increment jumped to 1 Qian per inch [7]. This tiered progression deliberately undervalued small timber while significantly boosting the price of large-diameter logs. For example, a log with a 3-foot circumference was defined as “Two Liang,” while a 5-foot log was termed a “Jin” (equal to 16 Liang and 3 Fen) [1].

Commercial Networks: From Majiazhou to Shangxinhe

The widespread adoption of the Longquan Code across half of China was driven by the sophisticated timber merchant networks of the Ming and Qing dynasties.

Guild Rivals: Hongdu and Linjiang

The Suichuan cedar trade was dominated by two powerful guilds: the Hongdu Guild (mostly merchants from Nanchang and Fengcheng) and the Linjiang Guild (from Qingjiang and Xingan) [8, 9]. These merchants purchased “Green Mountains” (standing timber) and hired professional rafters. Majiazhou (now Maji Town in Taihe) became the primary collection hub, filled with guild offices and trading houses [9]. Here, small rafts were combined into massive river rafts to sail down the Gan River.

Nanjing’s Shangxinhe Trade Rules

The ultimate destination for Longquan timber was the wealthy Yangtze Delta, with Nanjing’s Shangxinhe and Mianhuadi serving as the central markets [5, 10]. The Linjiang Guild held immense power at Shangxinhe. A stretch of the riverbank known as “The Beach” was patrolled by guild-hired security known as “Beach Lords” (Tan Ye). These roles were hereditary and verified by copper plaques, which were so valuable that they could be sold for 200–300 silver dollars during the Republican era [10]. The guild boasted over 400 firms, including the famous Huang Detai wood shop, which managed over 7,000 Code Units annually. Its proprietor, Huang Boren, became a legendary millionaire on the Nanjing waterfront [10].

The End of an Era: The 1955 Metric Transition

Despite its historical utility, the Longquan Code’s complex conversions and the monopolistic nature of the old guilds became incompatible with modern industrial requirements.

In 1905 (the 31st year of Guangxu), the Qing government attempted to standardize measurements, but the Longquan Code remained unshakable in the forest regions [11]. In 1928, the Nationalist government promulgated the metric system, yet timber merchants persisted with the “New Longquan Code” [7, 11].

The final shift occurred after the founding of the People’s Republic of China. To unify national standards and regulate resources, Suichuan established timber offices in 1951 [12]. In 1955, the state officially abolished the Longquan Code, replacing it entirely with the metric system (cubic meters) [5].

Calculations showed that one “Code Taen” roughly converted to 1.5543 cubic meters for mixed timber, while smaller “Xiao Fen” units were equivalent to 1.75 cubic meters [14]. Although the official system has changed, in the remote valleys of Suichuan, one can still occasionally hear local foresters reciting the measurement rhymes that have been passed down for three centuries [5].

Geographical Connections: The Timber Trail

  • Wudoujiang (Sanxi): The birthplace of the Code and home of Guo Weijing [1, 2].
  • Suichuan (formerly Longquan): The core production zone and start of the journey [15].
  • Majiazhou (Taihe): The largest upper-river hub and stronghold of the Hongdu and Linjiang guilds [5, 9].
  • Zhangshu (Qingjiang): Headquarters of the Linjiang Guild and home to one of China’s largest log yards [8].
  • Shangxinhe (Nanjing): The primary terminal market and center of the “Beach Lord” culture [10].
  • Wucheng (Yongxiu): The strategic junction where river rafts were reassembled before entering the lake [16].