Toilets are widely used in modern times. We can see them in almost all toilets. The toilet was invented by London watchmaker Cummings in 1775. At that time, the toilet was not as simple and convenient as the toilet now, but it was very simple. There is only one water tank, and then as soon as the handle is pulled to open the valve that can be opened and closed, the water flows down, and then the toilet begins to flush.
However, because it is more troublesome, if you want to flush water, you need to open two valves at the same time and operate together. So after the late18th century, British inventors improved some toilet designs according to Cummings' invention. For the first time, he canceled the design of two valves in the toilet and adopted some new structures, so that one valve in the water tank can automatically control the water, and he can block the water outlet when not in use. When water needs to be washed, it will be discharged. In addition, a pipeline is set up to ensure that the used sewage will not flow back and forth, and people will not smell the bad smell. Later, this toilet was patented at 1778.
Then in 1870, the British ceramic craftsman Taford designed an integral toilet made of ceramic materials. The overall cost of this toilet will be lower, because the first toilet is made of metal, so it is more expensive. It has an S-shaped drain pipe, which can store a lot of water, and the water will not flow out. When people are not using it, it can also block the smell.
The above story only represents my personal opinion. Please forgive me if there is any mistake.