When is a "dash" not a "dash"?
In 1875 (123 years B.P. ("Before Popov") , Winston Cole of England set the first official world record for the 100-yard dash. He recorded 1:15.0 using side-stroke, the racing stroke of the time. (It would be interesting to know how fast today's top swimmers can swim using this stroke.) Then came the English side-overarm swimmers who brought the record down to 1:05 by 1895. At this point, swimmers adopted a new stroke, the trudgen, and by the end of the 19th century, the great English swimmer, J. H. Derbyshire, had reduced the time to 1:00.2, an improvement of nearly 15 seconds in 25 years.