From the Oregon State University Archives:
Camp Cart, Showing Bed
Image Description from historic lecture booklet: “Carpenter in his geographical reader thus describes this kind of wagon:
‘What is that squealing outside the market? It sounds like a pig in the hands of a butcher. They surely cannot kill hogs here in the midst of the city. It is only the creaking of a farm cart which is bringing wheat to the market. There it comes through the door. it has wheels eight feet in height, with hubs as big around as your waist, and an axle as thick as a telegraph pole.
The cart has an arched cover of reeds over its bed. The kinds which have been sewed to the top are put there to keep the rain off the wheat. Such farm carts take the place of wagons throughout Argentina. they look very rude, but each cart will hold several tons–so much , indeed, that teams of twelve oxen are often hitched to one car.'”
Original Collection: Visual Instruction Department Lantern Slides
Item Number: P217:set 012 039
Preindustrial Craftsmanship 
In Mexico and Central America the semi trailers still have hooks on the bottom
side of the cargo bed. When it is siesta time you will find the driver and other
personnel in their hammocks. Siesta is sacred.
Yes indeed. Siesta is Sacred.