Leg press, deadlifts, RDLs, lunges, leg extensions, leg curls, hack squats, split squats. All those will hit your legs, plus there variations. Do some sprints, run hills, stairs, those will hit your legs. Im sure there are more lifts I can't think of this second as well.
While natural gas occurs in nature as a mixture of methane and other gases, propane is actually a byproduct of both petroleum refining and natural gas processing.
Propane and natural gas burn at nearly equal flame temperatures (3,560 degrees Fahrenheit). However, propane yields more energy per unit volume than natural gas does. For many years it was a commonly held belief that propane burned hotter than natural gas, but that was due to a miscalculation in the volume needed to create equal yields.