Listen to part of a lecture from a Botany class.
Hi, everyone, good to see you all today. Actually, I expected the population to be a lot lower today. It typically runs between 50 and 60 percent on the day the research paper is due. Um, I was hoping to have your exams back today, but, uh, the situation was that I went away for the weekend, and I was supposed to get in yesterday at five, and I expected to fully complete all the exams by midnight or so, which is the time that I usually go to bed, but my flight was delayed, and I ended up not getting in until one o'clock in the morning. Anyway, I'll do my best to have them finished by the next time we meet.
OK, in the last class, we started talking about useful plant fibers.In particular, we talked about cotton fibers, which we said were very useful, not only in the textile industry, but also in the chemical industry, and in the production of many products, such as plastics, paper, explosives, and so on. Today we'll continue talking about useful fibers, and we'll begin with a fiber that's commonly known as "Manila hemp".
Now, for some strange reason, many people believe that Manila hemp is a hemp plant. But Manila hemp is not really hemp. lt's actually a member of the banana family—it even bears little banana-shaped fruits. The“Manila”part of the name makes sense, because Manila hemp is produced chiefly in the Philippine lslands and, of course, the capital city of the Philippines is Manila.
Now, as fibers go, Manila hemp fibers are very long.They can easily be several feet in length and they're also very strong, very flexible.They have one more characteristic that's very important, and that is that they are exceptionally resistant to salt water. And this combination of characteristics—long, strong, flexible, resistant to salt water—makes Manila hemp a great material for ropes, especially for ropes that are gonna be used on ocean-going ships.
ln fact, by the early 1940's, even though steel cables were available, most ships in the United States Navy were not moored with steel cables; they were moored with Manila hemp ropes. Now, why was that? Well, the main reason was that steel cables degrade very, very quickly in contact with salt water. If you've ever been to San Francisco, you know that the Golden Gate Bridge is red. And it's red because of the zinc paint that goes on those stainless steel cables.
That, if they start at one end of the bridge and they work to the other end, by the time they finish,it's already time to go back and start painting the beginning of the bridge again, because the bridge was buit with steel cables, and steel cables can't take the salt air unless they're treated repeatedly with a zinc-based paint.
On the other hand, plant products like Manila hemp, you can drag through the ocean for weeks on end. If you wanna tie your anchor to it and drop it right into the ocean, that's no problem, because plant fibers can stand up for months, even years, in direct contact with salt water.
OK, so how do you take plant fibers that individualy you could break with your hands and turn them into a rope that's strong enough to moor a ship that weighs thousands of tons? Well, what you do is you extract these long fibers from the Manila hemp plant, and then you take several of these fibers, and you group them into a bundle, because by grouping the fibers you greatly increase their breaking strength—-that bundle of fibers is much stronger than any of the individual fibers that compose it.
And then you take that bundle of fibers and you twist it a little bit, because by twisting it, you increase its breaking strength even more And then you take several of these little bundles, and you group and twist them into bigger bundles, which you then group and twist into even bigger bundles, and so on, until eventually, you end up with a very, very strong rope.
该lecture告诉了我们一个叫Manila hemp 马尼拉麻的纤维植物。它的名字总是被和“大麻”搞混，但是这个植物是来源于菲律宾首都的一种类似香蕉的植物。它几乎是陆上最强纤维，航海的rope几乎全部都是用它来做的，它比钢缆好多了。
- Botany 植物学
- fibers 纤维
- cotton fibers 棉纤维
- textile 纺织品
- chemical 化学的
- plastics 塑料制品
- explosives 炸药
- Manila hemp 马尼拉麻
- hemp 麻
- hemp plant 大麻植物
- chiefly 主要
- Philippine 菲律宾
- exceptionally 异常地
- ropes 绳子
- cable 缆
- steel cables 钢缆
- moored 系泊
- degrade 降级 （这里特指 钢缆 在海里 特别容易被锈蚀和分解）
- San Francisco 旧金山
- Golden Gate Bridge 金门大桥
- stainless 防锈的
- zinc 锌
- anchor 锚
- extract 提炼
- bundle 捆
- compose 构成
- twist 扭曲
- it even bears little banana-shaped fruits. 它甚至结出一点香蕉状的果实。
- exceptionally resistant to salt water 极耐盐水
- moored with
- treated repeatedly 反复治疗 （这里特指反复给金门大桥涂以Zn涂层）