It is available to view and download at: http://victor.library.ucsb.edu/index.php/talent/detail/1440/Barton_Ward_vocalist_yodeling
and includes nine different recordings during the period 1909-1916. One of them is Barton’s performance of “I’m Dreaming of You” recorded on July 14, 1914.
At the Internet Archive: http://www.archive.org/search.php?query=creator%3A%22Ward%20Barton%22
two of Ward Barton’s early Victor records are available to download for free from the Public Domain under a Creative Commons License including a 1911 performance of “I’m Dreaming of You”