<a href="https://en.wikipedia.org/wiki/Steam_locomotive" class="extiw" title="en:Steam locomotive">Steam locomotive</a> “<a href="https://en.wikipedia.org/wiki/Adler_(locomotive)" class="extiw" title="en:Adler (locomotive)">Der Adler</a>”, which pulled the inauguration train of <a href="https://en.wikipedia.org/wiki/Bavarian_Ludwig_Railway" class="extiw" title="en:Bavarian Ludwig Railway">Germany’s first steam-powered railway</a>, in a <a href="https://en.wikipedia.org/wiki/Salt_print" class="extiw" title="en:Salt print">salt print photography</a> from the early 1850s.<br><p><i>Description at primary source page (translated):</i><br></p>
“This up to now sole known photography showing the original ‘Adler’ of 1835 was acquired by the Stadtarchiv Nürnberg (Nuremberg City Archives (NCA)) in 2001. It is a salt print made in the first half of the 1850s.  Origin and photographer are unknown.”
Unknown author<span style="display: none;">Unknown author</span>
<a href="//commons.wikimedia.org/wiki/File:Adler_Originalfoto.jpg" title="File:Adler Originalfoto.jpg">File:Adler_Originalfoto.jpg</a><br>which in turn states as source<br>“Fotographie, Salzabzug; <a rel="nofollow" class="external text" href="https://web.archive.org/web/20101207002930/http://nuernberg.de/internet/bahnjahr2010/geschichte_bildergalerie.html">https://web.archive.org/web/20101207002930/http://nuernberg.de/internet/bahnjahr2010/geschichte_bildergalerie.html</a>”