I found this historic and wonderful silent home movie on You Tube.
Seen here, are the old late 1940's and early 1950's era Twin Coach Company "Propane" powered buses, that had served the city of Syracuse New York for many years.
I was born in Chicago during 1962, and fondly recall riding the Chicago Transit Authority's own Twin Coach Company propane powered transit buses, during their final decade of service. I believe that the CTA began retiring these during the early 1970's. It is my understanding that the CTA also had several propane powered Mack buses during this time. Chicago's final remaining propane buses were retired for good in 1974.
It was good to see these classic buses agin, as this video brought back happy memories for me today.