Local 483 Apprenticeship Practice Exam

Understanding how invention and patenting relate helps answer this. The person who created the very first sprinkler head is credited as the inventor, but if that design wasn’t patented, there’s no patent holder to claim that innovation. Major Harrison is identified as the inventor of the first sprinkler head around 1864, and he did not patent it, which is exactly what the question asks for. The other names refer to later developments that did involve patenting, so they don’t fit the description of “invented the first sprinkler head but did not patent it.”