Edson Manufacturing Company of Boston, MA (now located in New Bedford) built pumps and related equipment. It is unclear what arrangement the two firms had for the manufacture of engines by Edson. I have seen an engine mounted on a Edison mud pump bearing the Fuller & Johnson name, and an engine mounted on another mud pump bearing the Edson name. The one main difference I noticed between the two engines is that the intake and exhaust valves are 180° apart on the Fuller & Johnson engine while they are 90° apart on the Edson engine. The door to the crankcase on the Edson engine has the Edson name and company location cast on it. All one can gather is that the Farm Pump Engine was definitely first, being patented in 1909, and that the two companies later came to an agreement to use the modified Fuller & Johnson design on Edson equipment.