A man named Orville Ewing travelled this country a generation or two ago, with a menagerie of sorts, living off postcard sales and his artistic talents.
Unfortunately, in the 30’s oil paints began affecting his health, and he had to switch to pencil and charcoal sketches. What was in the paint back then? Probably lead, for starters. Fortunately, he lived to about 90 years of age.
His covered wagon had a few concessions to progress, such as rubber tires instead of wooden wheels. Still, the menagerie only made about ten miles a day. Kind of tough to get to the fairs in a timely manner.