The video above shows the beautiful 1920s Doble steam car owned by Jay Leno (see this article). This magnificent vehicle represents the pinnacle of a technology that was already dead when it was built. A front-mounted boiler powers four cylinders at the rear, which drive the back wheels via spur gears (see below). There is no traditional gearbox or transmission. The steam is condensed and recycled, so that water does not have to be constantly replenished. All very efficient.
Leno says that “The last days of an old technology are almost always better than the first days of a new technology,” and aesthetically (in spite of my love of solar cars) he is probably right. Something similar can be said about the ultimate examples of castle-building, which occurred when castles were already obsolete (see below). So watch the video of this wonderful vintage car!