Google Humphry and follow the leads. Google his younger brother John also. Also cousin Edmund. There are some Roberts in the family.
Sir Humphry died childless and is buried in Geneva (see Google/Wikipedia.
Believe our side is down from John; believe he's gt, gt, grandfather. Grandfather was Frank; one of his brothers was Louis or ?? (they both settled in Ontario, Canada); other brother Louis or ?? settled in California near Los Angeles.