Full size picture of 3 meters long Luban ruler

The dimensions of the 3-meter-long Luban ruler are as follows:

The full name of the Luban ruler is "Luban construction ruler", also known as "Luban ruler". It is a measuring tool used in building houses. Similar to the curved ruler used by craftsmen today. The Luban ruler is about 46.08 centimeters long. According to legend, it was made by Gongshuban of the State of Lu in the Spring and Autumn Period. Later, the eight characters were added through the Feng Shui community to measure the good and bad luck of the house, and it was called the "door meter ruler".

Also known as "square ruler", it is a woodworking tool mainly used to check whether the planed boards, planks and structures are vertical and at right angles to the edges. 1 city ruler = 0.8 Luban ruler. Luban ruler was integrated with Dinglan ruler soon after its creation, and later with inches and centimeters. It is an important tool for measurement and correction. Due to its special functions, it is most widely expressed in Feng Shui culture and architectural culture.

Extended information:

Ancient man-made objects pay attention to auspiciousness, and the dimensions of buildings and furniture are accurately measured with Luban ruler. In the Forbidden City, all hall entrances, including furniture and other objects, are made according to the dimensions of Luban ruler.

For example, regarding the dimensions of doorways, the Qing Dynasty's "Regulations on Engineering Practice of the Ministry of Industry" listed 124 doorway dimensions determined according to Luban rulers, including 31 Tim Cai Gate, 31 Yishun Gate, and Guanlu Gate. There are 33 gates and 29 Ford gates. The strict production dimensions ensure the frequent appearance of the auspicious number "nine" in the Forbidden City building, which is in line with the emperor's requirements for the meanings of "nine-five honors", "eternal", and "the country lasts forever and never changes color".

The reasonable proportions also make the Forbidden City architecture durable and beautiful, making people impressed by the wisdom of the ancient ancestors of the Chinese nation.

The standard size of the Luban ruler is 46 centimeters, and the ancient Luban ruler was 46.08 centimeters long. The length of Luban ruler also has its scientific nature. The depth of the Taihe Gate Courtyard of the Forbidden City is 130 meters and the width is 200 meters. Its length-to-width ratio is 0.65, which is also very close to the golden ratio of 0.618.

The distance from Daming Gate to the center of the courtyard of the Hall of Supreme Harmony is 1.5045 kilometers, while the distance from Daming Gate to Jingshan is 2.5 miles. The ratio between the two is 0.618, which is exactly the same as the golden ratio. A large part of these golden ratio dimensions also benefit from the assistance of Luban ruler.

The golden ratio is a hidden scientific beauty. Most of the fine products made by traditional crafts follow this ratio. In addition to building dimensions, many dimensions of mahogany furniture are also measured with Luban rulers. A piece of mahogany furniture with exquisite beauty and high collection value is not only valuable for its material, but also for its strict size and perfect proportions.

The Luban ruler was the standard for measuring residences and furniture in ancient times. It has been passed down to this day. Some mahogany furniture companies still use this ancient tool to determine the size of mahogany furniture. This shows that its scientific basis is recognized by the public. For modern residences and furniture, Luban ruler still has a very important reference value.

Reference: Baidu Encyclopedia-Luban Ruler