Ida R. Forbes filed U.S. patent application Serial No. 144,791 for an 'Electric Water Heater' using thermostatically controlled electric heating elements.
On January 23, 1917, Ida R. Forbes filed a patent application with the United States Patent Office for an invention titled 'Electric Water Heater', assigned Serial No. 144,791. The application described an apparatus designed to heat water to a precise, pre-determined temperature using electric heating elements regulated by thermostatic controls.
This was a significant technical proposal at a time when domestic water heating was still overwhelmingly reliant on gas, coal, or wood-fired systems, and electricity in the home was a relatively new and still-developing convenience. Forbes's design anticipated the shift toward safer, more controllable, and more convenient home heating technology that would come to dominate the 20th century.
The filing itself represents an important milestone in the history of women inventors: navigating the patent process required technical literacy, legal knowledge, and persistence, all in an era when women were significantly underrepresented among patent holders in engineering and mechanical fields. Filing this application set in motion a process that would culminate, just over a year later, in the formal grant of a U.S. patent, cementing Forbes's place in the historical record of American inventors working on early electric household technology.