<!DOCTYPE html>
<html>
<head>
<style type="text/css">

#colset { -moz-column-count: 2; outline: 1px solid orange; }
.ib { height: 100px; display: inline-block; outline: 1px solid blue; }
div { outline: 1px solid green; }
span { outline: 1px solid magenta; }

</style>
</head>
<body>

<div id="colset"><div></div><div style="width: 10px; float: left;"><span> <span class="ib" style="width: 30px;"></span> <br> </span></div><span class="ib"></span></div>

</body>
</html>