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In the scope of "Tiangong Kaiwu", the uses of silver, river, mercury, and anchors have their own significance.
Silver is of high economic and technological value. In the field of money, it has long been an important medium of exchange, with various forms, from silver ingots to broken silver, widely circulated in commercial and trade exchanges, and maintained economic operation. In terms of craftsmanship, silver has good ductility and magnificent color. It is often carefully crafted into exquisite jewelry and luxurious utensils, which not only meets aesthetic needs, but also carries cultural and identity symbolism.
The river is primarily a water transportation channel. In ancient times, when transportation was inconvenient, rivers were the key route for long-distance transportation of bulk commodities, and the exchange of materials and commerce between the north and the south depended on this. At the same time, the river provides water for agricultural irrigation and guarantees the growth of crops, which is related to the national economy and people's livelihood. Furthermore, the river basin nourishes rich ecology, provides habitat for many organisms to reproduce, and maintains ecological balance.
Mercury has a unique position in the field of alchemy. Ancient alchemists believed that it could refine longevity pills. Although the concept is not scientific today, its exploration promotes the understanding of the chemical properties of mercury. In medicine, mercury compounds have been used to treat skin diseases such as scabies, but their application is now strictly limited due to toxicity. In addition, due to its special physical properties, mercury is indispensable in some traditional gilding processes, which can form a golden film on the surface of utensils, which is beautiful and durable.
Anchor, which guarantees the safety of ships docking. Navigating in rivers, lakes and seas, in the event of storms, shoals or when docking, anchoring can stabilize the ship in the designated position, avoid drift collisions, and ensure the safety of personnel and goods. It is essential for the smooth development of water transportation and fishing activities.

The physical properties of mercury, river and marsh mussels are as follows:
Mercury is a liquid metal at room temperature, with a shimmering silver light. Its weight and density are quite high, reaching 13.59 grams/cubic centimeter, which is higher than that of common metals such as iron and copper. Mercury has very good fluidity, drops on a plane, rolls freely, and is difficult to attach to other substances. Its melting point is extremely low, -38.87 ° C, so it is liquid at room temperature; its boiling point is not high, 356.6 ° C. Mercury has a certain volatility, and can slowly evaporate into mercury vapor in the air. This vapor is highly toxic. If inhaled, it can cause serious mercury poisoning and damage the nervous system, kidneys and other organs. The chemical properties of mercury are relatively stable, and it does not react quickly with common gases such as oxygen at room temperature. However, it can also react chemically when it encounters strong oxidants.
The river is a collection of water flows. Its water is impermanent, shaped with the trend, can be rushing and roaring, or it can be babbling slowly. River water is complex due to the inclusion of sediment, minerals, microorganisms, etc. Its density is slightly greater than that of pure water, about 1 gram/cubic centimeter, which is due to the impurities it contains. The temperature of river water varies with the season and region. It is warm in summer and cold in winter. And river water is soluble, soluble in oxygen, carbon dioxide and other gases, which is the basis for the survival of aquatic organisms. It is also fluid, can carry sediment, nutrients, etc., and plays a significant role in the ecological cycle.
The marsh mussel is also an aquatic shellfish. Its shell is hard, mostly oval-shaped, and has the function of protecting a soft body. The shell surface is often textured, rough or delicate, depending on the type of mussel. The marsh mussel is light in weight and has a slightly larger specific gravity than water, so it can inhabit the bottom of the water. Its body is soft and rich in nutrients such as protein. The marsh mussel has filter feeding properties. It feeds on plankton and organic debris in the water, and plays a positive role in the ecological purification of water bodies. Its growth is closely related to water temperature and water quality. In places with suitable water temperature and good water quality, the marsh mussel thrives.

Mercury is a highly toxic substance. It is cold in nature and heavy in quality. At room temperature, it can be in a liquid state with a metallic luster. Although the chemical properties of mercury, rivers, reservoirs, and bustards are not described in detail in "Tiangong Kaiwu", it can be slightly deduced from the experience and cognition of the ancients.
Mercury was often used in many fields such as alchemy, medicine, and metallurgy in ancient times. The ancients regarded mercury as a magical thing, because it can form amalgam with many metals, which seems to have extraordinary power. However, they are well aware that its toxicity is severe, and if you are not careful, it will cause poisoning, damage the viscera, and endanger life.
The river is a place where the water flow converges, and its chemical properties depend on the soil, minerals and other factors that flow through the place. River water often contains many anions and cations, such as calcium ions, magnesium ions, chloride ions, etc. The existence of these ions gives the river water specific chemical properties. If it flows through a place rich in metal minerals, the river water may carry trace metal ions.
The depositors are mostly places where the water flow is slow, where sediment, impurities, etc. settle and accumulate. The substances in the deposit are diverse, in addition to sediment, or contain a lot of organic substances and microorganisms. Under the action of microorganisms, these organic substances will undergo a series of complex chemical reactions, which affect the chemical properties of the deposit.
Bustard, as a rare metal, has a hard texture and a very high melting point. Although the ancients did not understand its precise chemical properties, they did know about its hardness and high temperature resistance. In high temperature environments, the chemical properties of the bustard are relatively stable and it is not easy to react with common substances. This characteristic makes it important in the manufacture of some special processes and utensils.
Although the chemical properties of mercury, rivers, lakes and bustards are not described in detail in "Tiangong Kaiwu", their characteristics can be peeked through the practical experience and cognition of the ancients. These understandings laid the foundation for future generations to explore the chemical properties of substances in depth.

There are three ways to combine "1 river - 4 rivers - 3 weirs".
First, manage the river channel first. View the terrain, smooth water, sparse congestion, and manage the river body. Make the river flow smoothly, so as not to flood. At the junction of rivers, guide its flow, level its trend, and avoid conflict. And build embankments to fix the banks of the river to prevent it from collapsing. This is the foundation of water management, and can pave the way for the weir.
Second, seek the connection between rivers and canals. Examine the source flow and water volume of the rivers, and plan the channels. Introduce the river into the river, increase the water potential of the river, so as to facilitate irrigation and shipping. When chiseling a canal, consider its height and height, measure its distance and proximity, so that the direction of the water is appropriate. A gate is also set up to store and discharge, if it is dry, the gate will be opened to divert water, and if it is waterlogged, the gate will be closed to prevent floods. In this way, the river and the river are mutually beneficial, and the function is greatly increased.
Third, the construction of the weir. The weir is also a tool for cutting water. Choose strong and thick materials, such as boulders and good trees. When building a weir in the river, the weir should be firm and smooth. Its height depends on the depth of the water and the urgency of use. The weir is formed, and water can be stored for irrigation, and water can be distributed for transportation. At the same time, a flood overflow mouth is
These three are parallel and interrelated. If the river channel is first managed, the secondary river channel is connected, and the weir gate is built later, then "1 river - 4 rivers - 3 weirs" can be completed, and water conservancy will be prosperous and people's livelihood will benefit.

When storing and transporting mercury, rivers, canals, and soybeans, everyone should pay attention.
Mercury is a highly toxic substance. It is active and easy to evaporate into mercury vapor, which is harmful to human health and the environment. When storing, a sealed device must be used and placed in a cool, dry, and ventilated place to prevent its leakage and volatilization. If it is accidentally leaked, cover it with sulfur powder quickly to synthesize it into mercury sulfide to reduce its harm. During transportation, it must also be tightly sealed, clearly marked, and transported in accordance with the regulations of hazardous chemicals. The escort must know its characteristics and emergency measures.
In rivers, the gathering of water is related to people's livelihood. When storing, it is necessary to keep the water source clean and prevent pollution from entering it. When damming and storing water, the impact on the ecology should be taken into account, such as fish migration and downstream water volume. When transporting, if it is transported by water, check the water level, water flow and water conditions to ensure the safety of the ship. And the things transported by the river must not pollute the river water, such as chemicals, which must be properly packaged.
Canals are mostly built for irrigation and water transportation. When storing and storing, dredge the canal to keep the water flow smooth, and fix the embankment to prevent leakage and burst. When transporting water, control the flow rate and flow, and allocate it as needed, so as not to cause waste or flooding.
Beans are ancient ritual vessels. They should be stored in a clean and dry place to prevent them from spoiling and deforming. When transporting, handle them with care and pad them with soft objects to avoid collision and damage, so as to have the solemnity and integrity of their ritual vessels.
All these objects must be carefully examined during storage and transportation, and according to their characteristics and regulations, they can be kept safe and safe.