The Patchwork of Measurements in a Divided Land

During China’s Spring and Autumn (771-476 BCE) and Warring States (475-221 BCE) periods, the absence of centralized authority created a fascinating mosaic of measurement systems. Archaeological evidence reveals striking variations between states in everything from vessel shapes to unit names and values. The Three Jin states used sheng, yi, dou, and hu for capacity measurements, while Qi employed sheng, dou, qu, fu, and zhong. Qin’s surviving artifacts show only sheng and dou, though texts mention tong, yong, and hu.

Weight measurements proved even more diverse:
– Qin: shi, jin, liang, zhu
– Wei: jin, yi
– Eastern Zhou bronzes: lüe, zhong
– Silverware: liang, zhu
– Zhongshan: dao, shi

The conversion systems formed a mathematician’s nightmare. While Qin standardized 24 zhu=1 liang, 16 liang=1 jin, and 120 jin=1 shi, Eastern Zhou used a 100-zhong=1 lüe system, and Zhongshan’s dao followed an 800-unit=1 shi standard.

The Politics of Measurement

Measurement systems became tools of political influence. The Qi state’s official measures used a 4-sheng=1 dou system (4×4×10 progression to zhong), while the influential Chen family adopted a 4-5-5-10 sequence. Archaeological finds like the “Chen Chun bronze fu” reveal the Chen measures were about 25% larger (20,500 ml vs. 16,400 ml) – a deliberate strategy to gain popular support by giving more when collecting taxes. Similar tactics appeared in Chu, where Bai Gong Sheng reportedly used “larger measures when giving out grain, lighter weights when collecting.”

Qin’s Metrological Revolution

Among the warring states, Qin demonstrated remarkable foresight in measurement reform. In 356 BCE, Shang Yang implemented sweeping changes to Qin’s measurement systems as part of his legalist reforms. The Records of the Grand Historian notes this standardization contributed significantly to Qin’s rising power.

Shang Yang’s system established:
– Length: yin, zhang, chi, cun
– Capacity: hu, dou, sheng, ge, yue
– Weight: shi, jun, jin, liang, zhu

The famous Shang Yang sheng (344 BCE) became Qin’s official standard, later verified by its inclusion of Qin Shi Huang’s 221 BCE unification edict. This bronze vessel, now in Shanghai Museum, provides crucial evidence of measurement continuity from reform to empire.

The Archaeologist’s Ruler

While no complete Qin chi (ruler) survives, scholars reconstruct its length through ingenious methods. The Shang Yang sheng inscription specifies its volume as 16 1/5 cubic cun. Measuring the vessel’s 202.15 cm³ capacity yields:
202.15 ÷ 16.2 = 12.478 cm³/cubic cun → cun=2.32 cm → chi=23.2 cm

This aligns with Western Han rulers found in Hebei (23.2 cm) and Guangxi (23 cm), suggesting Qin inherited its measurement system from earlier standards.

The Empire’s Measuring Tools

Over 110 Qin measurement artifacts survive nationwide, from Shaanxi to Shandong, Inner Mongolia to Jiangsu. These fall into two categories:

### Capacity Measures
– Bronze vessels: Often handled, square/oval shapes
– Ceramic vessels: Cylindrical, some marked with production locations
– Standard sizes: 1 sheng, 2.5 sheng (¼ dou), ⅓ dou, ½ dou, 1 dou

The 1963 discovery at Chifeng’s Spider Mountain revealed a 3,200 ml ceramic hu (about 1.6 Qin dou), its rope-patterned surface bearing the emperor’s edict.

### Weight Standards
Qin’s bronze and iron weights served as official reference standards across the empire. Notable examples include:
– Gao奴铜石权: A 30.75 kg bronze weight used from pre-unification through the Second Emperor’s reign, verifying the shi=120 jin standard
– Nanjing’s octagonal weight: 2.3 kg with dual edicts
– Chifeng iron weight: 31.431 kg, its surface covered with raised inscription

These artifacts confirm Qin’s jin weighed approximately 250g, a standard shared by Chu, Zhao, and Wei by the late Warring States period.

The Unification Legacy

Qin’s measurement revolution followed a clear progression:
1. Shang Yang’s 356 BCE reforms established consistent standards
2. Lü Buwei’s administration (249-235 BCE) instituted biannual verifications
3. Qin Shi Huang’s 221 BCE edict imposed these standards empire-wide

The Records famously summarizes: “Standardizing the laws, weights, and measurements; unifying axle widths; and creating uniform writing.” The Langya Inscription boasted: “Uniform measures and writing extend wherever sun and moon shine, boats and carts travel.”

By engraving edicts on measurement tools and marking production locations, Qin created an auditable system that balanced central control with local implementation – a bureaucratic innovation that helped sustain China’s first unified empire and set patterns that would endure for millennia. The Warring States’ measurement chaos ultimately gave birth to systems so effective they still shape East Asian metrology today.