That one you used the battery to start a little gas engine, like a motorcycle type engine or something. Got that running, revved it up and used it to crank the diesel main engine. You'd pull back on the compression lever and it'd start cranking the big engine and heating up the cylinders (no glowplugs, just spin it and make compression/heat), then after a few cranks of that, you'd let the compression lever halfway in and it'd start putting diesel in the (now warmed up) cylinders and it'd start smoking and popping, then it'd take off on its own and you'd push the compression lever back to its "off" position and the big diesel engine would be running..![]()
A lot like starting a hammond organ.
Those engines would last forever with little maintenace.