Using currents for discovery

Years ago I read about a mathematician who was conversant in fluid mechanics and understood how to calculate fluid flows, vortices, etc.. As I recall, the guy was a university professor and as a proof to his students of how one could use mathematics for creative purposes, he made a 3D computer model of the city center of Chicago. He then collected meteoroligical data showing wind velocity and directions, then used the placement of buildings to determine where vortices would coalesce and in the doing, perhaps collect lost items like paper money and other items of value.

From this calculate map, he took his students out to each spot where they found pockets of loose bills that netted him several thousand dollars. The students were both delighted and intrigued with this novel project and no doubt it inspired them to concentrate of their studies with regard to practical applications.

I was reminded of this vortices story when I chanced upon this brief article in a very old book;

"In the 'Gentleman's Magazine' (February 8th, 1767), is a curious notice of the mode of discovering the body of a drowned person: "An inquisition was taken at Newbury, Berks, on the body of a child nearly two years old, who fell into the river Kennet, and was drowned. The body was discovered by a very singular experiment.

After diligent search had been made in the river for the child, to no purpose, a two-penny loaf, with a quantity of quicksilver put into it, was set floating from the place where the child, it was supposed, had fallen in, which steered its course down the river upwards of half a mile, before a great number of spectators,

when the body, happening to lay on the contrary side of the river, the loaf suddenly tacked about and swam across the river, and gradually sunk near the child, when both the child and the loaf were brought up with grabbers ready for that purpose."