because “dentil”means teeth and it was supposed to look like a row of teeth.It looks something like a row of piano keys，too.
The wave is like this，something like an S lying down with a curl or scroll in one end.Of course you can see why it is called this if you have ever seen waves breaking on the shore.When I was a boy I used to make my capital S’s with many scrolls in each end until my teacher made me stop.
The running scroll is like this：
—one wave up and one down.This is one of the prettiest borders.
The astragal is like this：
Astragals were really little bones，but the astragal border looks to me like a string of beads—long beads with two round beads between themThe chain is like this：
—not a very pretty border，do you think so？
The cable or rope is like this：
The egg and dart is like this：
The egg was supposed to represent birth；the dart，death—birth and death，birth and death.Every man is born and dies.His son is born and dies.Generation after generation is born and dies，forever and ever.The astragal was always used below the egg and dart border.
The Lesbian leaf is like this：
The anthemion is like this：
—leaves arranged in a heart shape.
The Greek lily is like this：
The anthemion was often used with the Greek lily alternating.
These are called classic borders because the Greeks and Romans used them and anything Greek and Roman we call classic.
The next time you draw or mount a picture，suppose you try making a border for it of one of these classic designs.It’s fun.I’ve known boys to make such borders round the letters they wrote，round Christmas cards and even round their arithmetic papers，and some girls have embroidered handkerchiefs and towels with these designs，but they have to be done very carefully to look just right—one part exactly like every other，evenly spaced and in line.
【中文阅读】
男人们穿西服，打领带。女士们佩戴首饰和装饰品。建筑物也佩戴装饰物，以避免单调和粗糙的状况。我们把建筑物上的装饰物叫做“线条”和“边饰”。罗马和希腊的建造者用各式各样的线条或边饰，而当今的建造者也用几乎相同的线条和边饰。也许你从来没有仔细观察过门板、过道或窗户的边缘，天花板下图画的线条，或建筑物外围的其他边饰，但如果仔细观察的话，你将会大吃一惊，因为这些边饰都不是单调的线条，而是形状各异的。这些形态各不相同的线条还有不同的名称，就跟你知道的那些男孩女孩各有不同的名字一样，以便你能认识它们。让我来一一介绍吧：这样一种线条，从边缘看它是方的，简单到你认为根本就没必要给它命名。它被称作“平边”，也就是丝带或带子的意思。在古代男人和女人们在他们的头上都戴着一条头带，一来保持发型二来作为装饰。如今，建筑物也戴上了平边。平边从边缘上看就像左边的图。
如果平边的一侧往里陷，像一个方形的槽，就直接叫做凹平边。
还有一种线条，从边缘上看呈半圆形。建筑师称它“环状半圆线条”，但对木匠来说它就是“半圆形”。）如果这个环状半圆线条，或半圆形，往里陷，就形成一个圆形空洞或槽子。它的正确名称是“凹弧饰”，意为小洞穴，但木匠就叫它凹槽。如果一种线条，从边缘上看，像一个鸡蛋的曲线，就被建筑师称作“圆凸形线条”，意为鸡蛋形状的，但木匠们直接称它“鸡蛋线条”。还有一种线条，它的中心被挖空了，挖成鸡蛋形状的曲线。它被称作“凹弧边饰”。
如果一种线条的曲线看起来像是S 形，底部是空心的，它就被称作“双弯曲线”——就像“哦，天哪”这样的感叹！你在学校用的尺子就有这种双弯曲线的线条。还有一种线条也具有S 形状，但顶端是空心的。它被称作“反曲线”，意思是“像浪花一样”。当你看到这些线条时你能够认出它们并说出它们的名字吗？它们都是一对一对的——总共有四对。一个是实心的，一个是空心的；另外两个彼此互补。
平边先生和平边夫人环状半圆线条先生和凹弧饰小姐圆凸形线条先生和凹弧边饰小姐双弯曲线先生和反曲线小姐通常情况下，会采用两种或更多的线条，而不仅仅是某种单一的线条，用一种线条环绕另一种线条，把这些线条混合在一起就形成了多种美丽的图案。
在大多数混合图案中，方形平边被镶嵌在曲线线条中。这种方圆搭配使曲线线条更显突出。
在自己家中或别人家中看看能找到多少种像这样的线条。
边饰也有好几种。最简单的就是锯齿形，也称“波浪饰”），因为它很像士兵衣袖上的山形袖章，也有点像小孩第一笔涂鸦。
下一个简单的边饰是“扇贝形边饰”。之所以这么叫它是因为它的边缘看起来像扇贝。：
或者颠倒过来，就像这样：
像这样的就叫做“雉堞边饰”）：
雉堞边饰有时候也被称作“特洛伊墙”，因为特洛伊有围墙环绕，墙上留有空隙，士兵们可以射箭，城墙后面的断壁残垣还能让他们纵身跳下。
“回纹波形饰”像这样：
迈安德河是小亚细亚的一条蜿蜒曲折的河流。如果你在上学路上就这么走的话，我们就会说你在曲折前行。
“回纹饰”或“键形边饰”像这样：
它看起来像一排按键。“齿饰”像这样：
因为齿饰意味着与牙齿有关，而它看起来也像一排牙齿。它看起来也像一排钢琴键。
“波浪饰”是这样的，像一排S 横卧在一起，结尾处有小卷或卷轴。当然如果你曾看过海浪拍打着海岸的话，你就会知道为什么这样命名它。我小时候，就常常用卷轴画大写S，一个顶一个，直到老师叫我停下。
“滚动涡卷饰”像这样：
——一个浪头朝上卷来，一个浪头又向下拍去。这是最好看的边饰之一。“串珠饰”像这样：
串珠饰实际上就是小骨头，但串珠形边饰在我看来就像是一串珠子——每两个长珠子之间镶嵌着两个小圆珠。
“链条饰”像这样：
——这个边饰不太好看，你觉得呢？“缆绳饰”或“绳索饰”像这图：
“卵镖饰”像这样：
卵代表出生；镖象征死亡——生生死死，死死生生。人人都经历生和死。儿子出生，又去世。一代人去世，又一代人出生，世代循环，永远如此。
“莱斯波斯岛树叶饰”像这样：
“粽叶饰”像这样：
——树叶被安置在心形里。“希腊莲花饰”是这样的：
粽叶饰常常与希腊莲花图案交叉搭配。以上这些都被称作经典边饰，因为希腊人和罗马人都使用这种边饰，而凡是希腊和罗马的，我们都称之为经典。当你下次画画或装裱时，你可以试着用其中一款经典花样来镶边。这非常有趣。
我知道有些男孩在写信的时候会在信纸上镶边，在他们的圣诞贺卡上镶边，甚至在他们的算术本上镶边，而有些女孩喜欢使用绣有这些花样的手帕和毛巾。但这些活儿做起来必须小心翼翼才好——因为每一部分看起来必须和另一部分一模一样，即便是其中的空隙和线条也必须一模一样。
EARLY CHRISTIAN
早期基督教建筑
IF YOU get up in the morning at sunrise you might call yourself an early Christian.But early Christian in architecture does not mean early in the day；it means early in the history of Christians.Some of our finest buildings to-day are Christian churches，but once upon a time the only Christian churches were holes in the ground.
These holes were called catacombs.They were tunnels that were dug underground in Rome because the Christians were persecuted.That means they were punished just for being Christians and so they had to live in hiding.They hid in the dark secret passages of the catacombs.In the catacombs were rooms where Christians could “go to church.”There were rooms there，too，where dead Christians were buried safely.
It was like living in a coal mine，only worse，because when a Christian was caught by the Roman soldiers，he was generally given to the lions or burned alive or chopped to pieces.Suppose you had to live down underground and never could come up without danger of getting caught and killed.It might be exciting and fun at first，but when you found some of your friends or perhaps even your brother or your aunt or your father had been carried off and put to death，it would not be fun at all.
So you can imagine how glad the Christians who lived in the catacombs must have been when the Roman emperor himself became a Christian.