100
The Montgolfier brothers, Joseph-Michel and Jacques-Étienne, had a total of six siblings. They were part of a family of eight children. Their parents were members of a prosperous family of paper manufacturers. The brothers are best known for their pioneering work in ballooning.
They only made 2 inventions
the Montgolfier brothers were 2 french brothers called "Etienne and Michel Montgolfier" later in their life they tried very hard to create the "hot air balloon"! It took so many tries they almost gave up but eventually they made it and after experimenting for a year and a half they had invented the hot air balloon! (Probably not true!)
He made 5 inventions.
over 1000 inventions from "The Wizard of Menlo Park"
29
A lot.
he made many inventions that were very succsesful and they were made with 19 letters of the alphabet.
This depends on which scientific invention you are referring to. I would say that yes, many inventions make us happy.
120
over 300
over 1000