100年前的生活妙招：如何画出完美的椭圆？

People don't often look back on the early 1900's for advice, but what if we could actually learn something from the Lost Generation?
通常人们不会为了求取生活妙方而去回顾20世纪初的年代，不过如果那个“垮掉的一代”真的能对我们有所助益呢？

The New York Public Library has digitized 100 "how to do it" cards found in cigarette boxes over 100 years ago, and the tips they give are so practical that millennials reading this might want to take notes.
纽约公共图书馆将一组100多年前的香烟盒上的“生活妙招”卡片进行了数字化处理，这些卡片上的小贴士实在太实用了，二十一世纪的我们看到了也会多加留意！

How to Draw an Ellipse with String
如何用绳子画出椭圆

Size of ellipse having been determined, focuses are found by measuring off the short diameter(or width of ellipse) form ends of long diameter(or length of ellipse). Two pins should be fixed, and string or thread looped round, as shown in picture, Length of loop should be from A to B.
确定想要画出的椭圆的大小后，通过测量椭圆的短轴和长轴确定出椭圆的焦点位置。将两枚细针固定在焦点的位置上，如图所示，让细绳或细线绕出一个圈。绳圈的长度即A点到B点的距离。