Looks like he is out with the Vagabonds collecting some information on the use of ethanol!
Who is the person on the far left? I can identify the rest - Calvin Coolidge, Henry Ford, Thomas Edison.
Gentleman at the far left is John Calvin Coolidge, Sr.
If you take a little time, you can very easily figure out where and when the photo was taken.
By the way, it's not a barrel. It's a sap bucket which makes total sense if you know where the photo was taken. Note the name on the bottom of the bucket.