Chapter 24 of 100

Chapter 24

14 min read3,575 words

It is said that the one-way journey to Zhenzhou is over a hundred li. Regarding the issue of li, Hong Tao and Chen Ming'en had discussed it several times but still couldn't figure out exactly how long a li was in the Song Dynasty. The unit of li was not clearly defined by the Song Dynasty government, and in the Song Dynasty's system of weights and measures, the highest unit was the yin. One yin equals ten zhang, one zhang equals ten chi, one chi equals ten cun, and one cun equals ten fen, with no units above or below these. This system of units was established during the Qin Dynasty and had not been significantly altered since, at least not in the Song Dynasty, where the official units were these five.

Hong Tao did some conversions himself. If ten yin equal one li, it would be only about 300 meters, which seems a bit short. According to the hexadecimal system, if 16 yin equal one li, it would be about 480 meters, roughly equivalent to a modern li. In fact, if Hong Tao had studied history more thoroughly, he would have known that his calculations were incorrect. Ancient texts recorded that before the Qing Dynasty revised the length units, each dynasty used 18 yin to equal one li. The reason for this is unclear, but it is recorded as such. This means that a li in the Song Dynasty was slightly longer than a modern li, about 550 meters.

Whether it's 480 meters or 550 meters, the difference is not significant for Hong Tao. In other words, the sea route from Ningyuan River to Zhenzhou is about 50 kilometers. At the current speed of the small wooden boat, it can sail at about 3 knots with a 3-4 level wind, which is about 5.5 kilometers per hour, roughly equivalent to a brisk adult walking pace.

Don't underestimate this walking speed. Walking requires physical effort. Can you walk briskly for an hour? Can you walk briskly for ten hours? Can you walk continuously for ten hours without stopping? A sailboat can, and not just for ten hours. As long as it doesn't enter a calm zone, it can sail regardless of the wind direction, 24 hours a day, for several days or even weeks. So, although the speed is not fast, it is still much faster than walking, especially when carrying a load.

When it comes to the speed of sailboats, Hong Tao doesn't need to ask anyone; he is clear about it. He studied this during his sailing license exam, looking up a lot of information in the library, both modern and ancient. This shows how much effort he puts into his hobbies, fearing that someone might stump him. If you ask him if he understands listed companies, he can confidently answer, "No!" But if he is stumped on a hobby-related question, especially one about his current project, he would feel very embarrassed.

How fast could sailboats travel during the Tang and Song Dynasties? Historical records provide answers. Zheng He's treasure ships could travel about 100 nautical miles per day, averaging only about 4 knots. Another recorded example is the Qing Dynasty's ocean-going sailboat, the Qinying, which sailed from Boston to London in 21 days, covering a total distance of 5,264 kilometers, with an average speed of about 10.44 kilometers per hour, or 5.7 knots. This is not an extreme case of a 6-level side wind; there were also times of 1-level headwinds.

The Ming Dynasty document "The Record of the Mission to Ryukyu" records that during the Jiajing and Wanli periods, the journey from Fujian to Shuri (now Naha) took seven days, and at most ten days. This suggests that the sailboats of the time could travel about 80 to 120 kilometers per day.

The above speeds are for Chinese hard-sail boats. Were European soft-sail boats faster? This requires analysis. Records show that in July 1660, the Governor of Batavia sent Van der Lan with 12 sailboats to Taiwan, taking 65 days. In 1661, Jacob Cauw led 10 warships to Taiwan, arriving on July 18 after 38 days. This suggests that European soft-sail boats could travel about 60 to 100 kilometers per day.

From this, it is clear that Chinese ancient sailboats were not fast, and European sailboats during the Age of Exploration were not much faster. The average speed of a galleon was about 7 knots, and Mediterranean rowing sailboats could only maintain a speed of about 8 knots for one day, after which the rowers would be too exhausted to continue. Even in extreme sprints, they could reach speeds of over 11 knots, but only for 20 minutes, and these were not suitable for long-distance voyages.

These speeds are for ocean-going merchant ships and armed merchant ships. If they were warships, the speed could be slightly higher, but not by much. Even the British warships of the late Qing Dynasty, which were from the 19th century, had an average speed of less than 10 knots, otherwise, they would have been replaced by steamships that could maintain a speed of 11 knots.

Of course, there were exceptions. In both ancient China and Europe, some coastal ships could travel faster. For example, in the coastal areas of Fujian, there was a sailboat with a displacement of about 200 tons, locally known as the "Green Eyebrow," with three masts and five to six large sails. It had a recorded average speed of 9 knots. However, this type of ship was more suitable for warships, with a slender and long hull that could not carry much cargo, so it was also called a "bird ship."

Someone might ask, why could the sailboat Hong Tao used for his circumnavigation reach a speed of 30 knots? The answer is: technology! Advanced technology!

Modern sailboats are a completely different concept from medieval sailboats. First, the hull design is computer-aided and is very small, making it suitable for high-speed travel. Second, the materials used, from the hull to the masts to the sails, are both light and strong, with a high sail-to-weight ratio. In ancient times, such high-quality sails and sturdy masts were impossible to find. If the masts were made taller and the sail area increased, the masts would break before the boat could reach high speeds. Finally, the purpose of the boats is different. Ancient sailboats, whether merchant or warships, were primarily practical, carrying many goods and people. Modern sailboats are mainly for recreation and racing, typically operated by one or two people, without much consideration for cargo capacity.

Additionally, the use of modern sails is entirely different from ancient sails. Although they look similar, there are significant differences. Ancient sails primarily relied on favorable winds, a limitation of their technology. They did not understand the Bernoulli principle and naturally assumed that favorable winds were faster. However, after the invention of the airplane, people discovered a technique to create pressure differences using the wing principle, which modern sailboats are designed to utilize. In side winds, they can travel much faster than in favorable winds.

In fact, modern ocean-going cargo ships are not very fast either, typically traveling at speeds of over ten knots. Even warships cannot maintain high speeds for long periods, as the machinery cannot handle it. Therefore, for long-distance voyages at sea, the main parameter is the average speed. High-speed travel is only applicable in special situations, not unimportant, but certainly not the primary concern.

At this speed, considering headwinds and rest times, it would take Chen Ming'en and his team about 20 hours to travel from the mouth of the Ningyuan River to Zhenzhou, and the round trip would take about two days. Selling goods and purchasing goods in the area would take at least four to five days before they could return.

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