Mr. Kravitz may now be the vacuum cleaner's foremost historian, or at least apologist. His research has consisted mainly of collecting information from the vacuum makers and reading a children's book on the subject. Most recently, he delivered a lecture at the Science, Industry and Business Library of the New York Public Library on the subject, attended by about 35 curious vacuum cleaner enthusiasts. By Mr. Kravitz's estimation, vacuum cleaners rank among the most important inventions of the century. Those days are long gone.
Academic historians disagree.
Vacuum cleaners did not necessarily reduce housework because they raised the standards of good housekeeping enough to require the same amount of time, said Nancy Tomes, professor at the State University at Stony Brook. But by the 1920's, when scientists concluded that germs traveled from body to body, not via the floor boards, vacuums had become mainly for domestic aesthetics, she said. Mr. Kravitz, however, prefers to start his history earlier, in the 1870's, when one night at a London restaurant the engineer Hubert Cecil Booth placed his handkerchief between his mouth and a velvet couch and breathed in. He found a film of dirt on the other side of the cloth. Cleaning had previously meant enormous coal-powered fans for blowing.