Air conditioning
In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. There, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.
Willis Bradley Haviland
Willis Hoag Haviland, a farmer, and his second wife, Hannah Wing Haviland, were first cousins once removed, which caused friction with the Quaker Meeting to which they belonged, ending in severance with the church. Hannah Wing Haviland's half-sister was Ann Elizabeth Button (27 Mar 1823 – 15 Mar 1849), wife of David Jay Haviland (29 Mar 1820 – 13 Aug 1868); they were the parents of Elizabeth R. Haviland (1845–1888) who would marry Duane Williams Carrier and have only child Willis Haviland Carrier in 1876, later the inventor of modern air conditioning technology. Willis Haviland Carrier was named after Willis Hoag Haviland, who after Elizabeth's father's death took care of her before she was married. (Willis Hoag Haviland was also Elizabeth's uncle-in-law.)