What Contributions to today's society were made by Rufus Strokes and Lewis H. Latimer?

Rufus Stokes was born in Alabama in 1924. He later moved to Illinois, where he worked as a machinist for an incinerator company. In 1968, he was granted a patent on an air-purification device to reduce the gas and ash emissions of furnace and powerplant smokestack emissions. The filtered
output from the stacks became almost transparent. Stokes tested and demonstrated several models of stack filters, termed the "clean air machine", in Chicago and elsewhere to show its versatility. The system benefited the respiratory health of people, but also eased the health risks to plants and animals. A side-effect of reduced industrial stack emissions was the improved appearance and
durability of buildings, cars, and objects exposed to outdoor pollution for lengthy periods.

Lewis Howard Latimer was born in Chelsea, Massachusetts on September 4, 1848. He learned mechanical drawing in the patent attorney office of Crosby and Gould, Boston, Massachusetts. He invented a toilet system for railroad cars in 1873, referred to as water closet for railroad cars. He also invented an electric lamp with an inexpensive carbon filament and a threaded wooden socket for light bulbs. He supervised the installation of carbon filament electric lighting in New York City, Philadelphia, Montreal, and London. He was responsible for preparing the mechanical drawings for Alexander Graham Bell's patent application for his telephone design. Lewis Latimer had the distinction of being the only African American member of the Edison Pioneers, a member of Thomas Edisons engineering division of the Edison Company. He joined the Edison Electric Light Company in 1884 and conducted research on electrical lighting. In 1890 he published Incandescent Electric Lighting, a technical engineering book which became a guide for lighting engineers. For years he served as an expert witness in the court battles over Thomas Edison s patents. At the time of Latimer's death in 1928, the Edison Pioneers attributed his "important inventions" to a "keen perception of the potential of the electric light and kindred industries."