Sandals, literally mean shoes that are cool to wear, are footwear with exposed toes, mainly worn barefoot. The most common sandals today are straw sandals (straw shoes) and wooden clogs.

When the weather is hot in summer, ordinary people can wear straw sandals and wooden clogs, but soldiers cannot marching and fighting in wooden clogs. Therefore, since ancient times, ordinary soldiers have used straw sandals as sandals.

Even barefoot.

In an era when soldiers could not even have enough food, it would be nice for soldiers to have a pair of cloth shoes. Anyway, the generals were all thinking about the troops, and the well-equipped equipment had never had anything to do with ordinary soldiers.

When fighting, ordinary soldiers are "mixed fish", and no one cares whether the soldiers' shoes are good or not.

However, Yuwen Wen felt that this view has changed.

Cavalry is the main force in combat, but infantry is not garbage. It is also powerful if used properly. Infantry marches on their legs, traveling through mountains and rivers, and crossing mountains and ridges. If their shoes are not good, they will hurt their feet.

Once a soldier's soles are injured, "non-combat attrition" will occur, affecting his combat effectiveness.

So, today he and his old subordinates personally experienced the comfort of the new sandals. They didn’t walk on the road, and specifically walked on sand, slopes, mud and woodland. To see if this kind of rubber sole sandal can ensure that the feet of the wearer are intact after a long marching.

At this moment, the group sat under the big tree, holding the shoes they were wearing and pondering carefully to see if there was anything that needed to be improved.

This sandal is a rubber sole, and is woven into the nose and ears of the shoe, forming a rubber sole straw sandal.

When the new sandals were finalized at the beginning of the year, they used Eucommia ulmoide soles. However, later, Beiyang Trading Company transported a large amount of rubber from the Americas. The characteristics of rubber are similar to Eucommia ulmoide, so there are "derived" rubber-soled straw sandals.

Brother Chen Wu took the lead in expressing his opinion: "Your Majesty, this rubber sole is similar to the Eucommia ulmoide sole. It is elastic, soft and wear-resistant. When you wear it on your feet, you jump down from a high place. When you land, you don't feel the sole of your feet numb. It seems that it is the cushioning effect of the soft sole."

"Walking on the gravel, I didn't feel hurting my feet. The soles of the soles and soles of the feet were patterned. They had anti-slip effects and could also sweat. Weichen's sweaty feet, who walked barefoot so far, didn't feel slipping the soles of the feet."

Hao Dadan held the shoes, then twisted the sole, then bent the sole, as if it was bent, and finally let go, the sole "bounced" back and returned to its original state.

He sighed: "Your Majesty, this rubber is as elastic as Eucommia ulmoides. It is very elastic. No matter how far you walk, you won't feel tired... Oh, the soles of the shoes have thorns, and I have never found them."

Hao Dadan pulled out the thorn and compared the length: "If it were thinner straw sandals, they might have been stuck to the soles of their feet."

He looked at the soles of a considerable thickness and sighed: "I didn't expect there was such a good thing in America."

"That's right, so America is a good place." Yuwen Wen nodded and introduced rubber from America to his old subordinates.

Eucommia ulmoides are divided into raw and cooked rubber, and the same is true for rubber.

There are many places in America where rubber trees grow. After cutting their bark, the collected sap solidifies and becomes rubber.

This is raw rubber, elastic. Native Americans use rubber to make rubber balls to conduct various competitions.

Raw rubber, like raw Eucommia ulmoides, is elastic, but has weak elasticity. The colloid is relatively hard at room temperature. It becomes soft when it is heated, and becomes hard and brittle when it is cold, and its wear resistance is not very good.

Raw Eucommia ulmoides must be processed through a process called "Vulcanization" and become cooked glue. After this treatment, the elasticity will increase significantly at room temperature and have good wear resistance. It will not become soft due to exposure to sunlight, nor will it become hard due to slight cold.

The same is true for rubber. The rubber shipped from America is raw rubber. After being treated with the "vulcanization" process, it is vulcanized rubber (cooked rubber), which has better performance than Eucommia ulmoide.

The reason why this kind of straw sandals is used to make the soles of rubber (eutectic ulmoides) is still used to make the shoe nose and shoe ears is to consider the reality: rubber sandals made of rubber, the shoe nose and shoe ears are still not soft enough and will rub your feet.

Secondly, during many long-term trials, the experimenters found that the connection between the nose, ears and soles of the shoe are easily broken, and once it is broken, it is difficult to make up, so a pair of shoes is scrapped.

Therefore, in order to ensure the applicability of new sandals, rubber (Eucommia ulmoides) is used as the sole, and then holes are left to facilitate the braid of the nose and ears of the shoe with straw rope, and then connected to the sole.

In this way, once the straw rope is broken, the soldiers can use the materials locally and weave the straw rope to make a new shoe nose and ears, which can still be worn.

Similarly, it is also possible to use hemp rope or cloth strip or leather strip for the nose and ears.

Rubber has entered the Central Plains for a short time, but the Eucommia rubber industry in the Central Plains has been developing for more than 30 years. Therefore, when rubber comes to the Central Plains, a series of processing technologies (including vulcanization) can be used on rubber.

So, rubber-soled straw sandals appeared soon.

However, there are more than this type of new style shoes.

Canvas shoes with rubber sole and cotton shoes with rubber sole can be suitable for different regions.

The rubber-soled canvas shoes have uppers that can protect the soles of the feet and the ankles. When soldiers cross mountains and ridges, they walk everywhere in the mountains and forests with stones and thorny areas below the ankles will not be easily scratched or scratched.

Only a journey of thousands of miles can be guaranteed.

Therefore, rubber-soled canvas shoes will be military shoes promoted by the imperial court on a large scale in the army, and they will be available in different sizes to suit the soles of different soldiers.

In winter, if it is not too cold in the south, soldiers wear thick socks and then wear rubber-soled canvas shoes to ensure that their feet are warm.

If you are in the north, you have to wear rubber-soled cotton shoes and cotton boots.

Yuwen Wen was barefoot and holding rubber-soled straw sandals and said: "The court cannot make every soldier have a horse to carry on, but at least every soldier has reliable quality shoes, socks, summer and winter, as well as spare shoes, and how many pairs of socks can be worn in turn."

"The army is the cornerstone of the country, and soldiers are an important part of the army. Only by protecting the soldiers' feet can they march thousands of miles, cross mountains and ridges and detours, and the combat effectiveness of the army is guaranteed."

"Everyone is a long-time general who has led his troops for many years. He should know that the military orders are as high as a mountain. The army must arrive at the marching period. Then, even if it rains heavily, he must rush to the destination, regardless of wind and rain."

"So the question is: in the summer, you can wear rubber-soled straw sandals, rubber-soled canvas shoes or straw sandals. What about winter? It's okay in the south, but it will snow heavily in the north. Is it good to have a rubber-soled cotton boots marching in the mud mixed with ice and snow? Is that good feeling?"

"The boots are soaked and can only be dried by fire, but what if there is no time to dry them? The soldiers marched for days in wet and cold cotton boots, and the consequences are toes and soles of their feet, and they will hurt after taking a step."

"In this state, if you go to the battlefield, your combat effectiveness will be greatly reduced, so the company has developed a new type of rain boots." Yuwen Wen asked his entourage to take out a few pairs of long boots and show them to everyone.

These long boots are common styles of long boots in later generations.

Yuwen Wen introduced: "This is a new type of water shoes, high-top and knee-length, all made of Eucommia ulmoides or rubber. It has excellent waterproofing performance. When you wear your feet and march in the mud, you are not afraid of your feet being soaked in the mud, nor are you afraid of your shoes falling into the mud and not being able to pull out, so you can only march barefoot later."

Chen Wudi and others got the new water shoes, took them in their hands and watched them carefully, then put them on, walked back and forth, and even ran to the stream next to them to wade and walk for a distance. After returning, they praised the intersection: "It's indeed waterproof!"

Yuwen Wen nodded and said, "Of course, these water shoes are waterproof, but they also cover their feet. When they march for a day, their feet will inevitably smell bad, and the sweat from their feet will make the socks and the inside of the shoes wet."

"However, drying socks is easy, and it is not difficult to dry the water shoes with a piece of cloth. Anyway, it is much easier than drying cotton boots."

Tian Zhengyue stroked the water shoes and asked, "Your Majesty, these water shoes are really good. Can they be mass-produced and distributed to all soldiers of the army?"

Yuwen Wen replied: "It's difficult, so it can only be distributed in batches, because the yield of Eucommia ulmoides is still small, and rubber is not a specialty of the Central Plains, so it needs to be introduced."

Speaking of this, he added: "Yousi started introducing rubber this year. According to the Native Americans, it is necessary to use seedlings to introduce them. If they are planted with seeds, it is difficult to plant them. Moreover, rubber likes high humidity and high heat. At present, it can only be tried in Qiongzhou, Jiaozhou, Luzhou and Nanyang areas."

"Even if you live, it will take about ten years to grow up and produce rubber..."

More than ten years later, it is still unknown whether he is alive.

This topic is a bit heavy, and Chen Wudi quickly smoothed out: "Your Majesty, as the saying goes, 'Previous men planted trees and later became a coolie', when the rubber became a forest in the future, children and grandchildren can use various magical rubber products."

"Yes..." Yuwen Wen nodded, thought for a while, and smiled: "Do you know that this rubber tree is divided into species and is divided into legitimate and illegitimate."

This statement is interesting, everyone listened attentively, and Yuwen Wen told it.

He himself knew that rubber was native to the South American jungle.

However, in fact, there are also Central America.

The Beiyang Trading Company expedition team discovered that there were also rubber trees in Central America. Local natives began to use rubber to make various rubber products a long time ago, including rubber balls for competitions.

This surprised Yuwen Wen, but after reading the investigation report of the expedition team, he suddenly realized that there is a difference between rubber trees.

The rubber trees in South America are three-leaf rubber trees with high rubber yields. They are probably the ancestors of rubber trees that were widely planted in later generations, but there are differences in rubber trees in Central America.

Yuwen Wen thought that the rubber trees in Central America were probably "subspecies" and their yields were not good, so they had no future in future development and were gradually forgotten.

Of course he would not say this kind of knowledge, but he introduced it to his old subordinates in another way:
Chapter completed!