This html pages demonstrates the placement of captions under images. See http://alistapart.com/articles/practicalcss/, http://www.cs.tut.fi/~jkorpela/www/captions.html, http://randsco.com/index.php/2005/01/31/css_photo_caption_zoom, and http://www.w3.org/Style/Examples/007/figures.html
The height has not been set in the css file, because for thumbnails its needs to be set in the page, as the wiki user can choose the thumbnail height.
image 1
My caption
image 2
My caption
image 3
My caption might be longer than the picture is wide
its up to the user to add breaks
as they require
image 4
My caption
image 5
My caption
image 6
My caption
image 7
My caption
might
take
several
lines