iframe_embed.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta name="generator" content=
  "HTML Tidy for Mac OS X (vers 31 October 2006 - Apple Inc. build 15.18.1), see www.w3.org" />

  <style>
    iframe {
      display: block;
      width: 550px;
      height: 320px;
      margin: 100px auto;
    }
  </style>
  <title>Altair iframe embed</title>
</head>

<body>
  <iframe src="timeline_bar_data_separate.html"></iframe>
</body>
</html>