可变高度的浮动元件将兄弟姐妹向下推

问：

我有 6 个元素，应该产生两行，每行 3 个元素，所以我浮动了它们。但是元素的内容差异很大，当一个较高的元素阻止后续的兄弟姐妹一直向左漂浮时，布局就会中断：

下面是 CSS 示例：

figure { width: 30%; float: left; margin-left: 1%; font-size: small; outline: solid #999 1px; }
img { max-width: 100%; }

和 HTML：

<figure>
  <img src="http://placekitten.com/150/200?image=1" alt="Kitten 1" />
  <figcaption>Bacon ipsum dolor sit amet short ribs pork chop pork belly spare ribs shoulder tri-tip beef ribs turkey brisket short loin tenderloin ground round. </figcaption>
</figure>
<figure>
  <img src="http://placekitten.com/150/200?image=2" alt="Kitten 2" />
  <figcaption>Short ribs cow corned beef, beef tenderloin swine biltong short loin. </figcaption>
</figure>
<figure>
  <img src="http://placekitten.com/150/200?image=3" alt="Kitten 3" />
  <figcaption>Boudin chuck ground round, pig pastrami salami turkey ham hock beef ribs tongue. </figcaption>
</figure>
<figure>
  <img src="http://placekitten.com/150/200?image=4" alt="Kitten 4" />
  <figcaption>Tri-tip pork loin tongue corned beef shankle ball tip. </figcaption>
</figure>
<figure>
  <img src="http://placekitten.com/150/200?image=5" alt="Kitten 5" />
  <figcaption>Turkey swine tenderloin spare ribs sausage filet mignon hamburger. Leberkas andouille prosciutto, bresaola tri-tip short loin meatloaf shank pig shoulder spare ribs ribeye. </figcaption>
</figure>
<figure>
  <img src="http://placekitten.com/150/200?image=6" alt="Kitten 6" />
  <figcaption>Pastrami andouille tongue tri-tip jerky.</figcaption>
</figure>

还有一个例子 JSFiddle： http://jsfiddle.net/KatieK/5Upbt/

如何让第二行元素在前 3 个元素下方对齐？figure

HTML/CSS 解决方案比 JavaScript/jQuery 解决方案更可取。