swimming

Yes, perhaps Franklin was a poor choice as he was a health fanatic, who did invent the "air bath," and was also noted for his penchant for insisting on opening the windows for fresh air when he slept. This always caused problems when he was sharing a bed at an inn, because most folks then were paranoid of drafts (not to mention insects). Remember, this was the late 1700's, and some European folks were venturing back into the water, especially in the US where they saw that the swimming and bathing habits of the indigenous people caused no ill affects. As noted in your citation, Keiva, swimming was quite a novelty then, and Franklin could've made a fortune opening a swimming school on the European continent. Found this on the International Naturists Site
http://clothesfree.com:

Benjamin Franklin, U. S. statesman and inventor and --John Adams, U. S. President Franklin, would you believe, was a practicing 18th century nudist! He took his "air baths" by sitting in the buff in front of an open window. President Adams regularly swam nude in the Potomac river. Anne Royall, a journalist, heard of Adam's early morning skinny dips. After being refused interviews with the President several times, she
went to the river, gathered his clothes and sat on them until he agreed to speak to her. Before this, no woman journalist had ever interviewed a president. (Way to go, Annie!)

Also this, from the IEEE History Center site:

Benjamin Franklin's Work in London, 1757-1775, 36 Craven Street

Franklin, considered one of the founders of modern Physics, was already a famous scientist when he arrived at Craven Street in 1757. He resided there for 16 years.
In the room behind his parlor, Franklin constructed a laboratory for his research. Here he continued his
electrical experiments. He proved that electricity has a positive and a negative charge, invented an improved generator and storage batteries. Franklin had proved that lightning is electrical. He had flown metal-tipped kites during thunderstorms and "captured the fire of heaven". He continued these experiments, sending kites aloft along the Thames during thunderstorms. By experimenting with different metals and shapes he was able to perfect his famous lightning rod conductor. This was such a success that Lightning Rods were placed on St. Jame's Palace (greatly to the annoyance of George III) and on the other great State buildings, churches and cathedrals in London.
At Craven Street, Franklin perfected his famous Stove, which is still in wide use today. It burns its own smoke and saves fuel.
During a hot London summer Franklin invented the Air Bath, the forerunner of Air Conditioning.