Final answer:
Count Rumford concluded that thermal energy and mechanical energy were related based on an observation during his cannon experiments, while James Prescott Joule's experiments established that heat is a form of energy and not a fluid. Count Rumford's observations of heat production during cannon boring, along with Joule's work on the mechanical equivalent of heat, provided strong evidence that heat is not a fluid but a form of energy related to mechanical work.
Step-by-step explanation:
Count Rumford observed the seemingly endless supply of heat generated when cannons were bored, and how this heat could continue to be produced as long as mechanical work was applied. This led him to conclude that thermal energy (heat) and mechanical energy were related because the work that was done converted mechanical energy into heat. Furthermore, the evidence that contradicted the idea that heat was a fluid, which was known as the caloric, came from the observations that the amount of heat could be continuously produced through work whereas a fluid would be expected to run out after some time. This observation aligned with the later work of James Prescott Joule, who demonstrated the mechanical equivalent of heat, further debunking the caloric theory.
Count Rumford made an observation during his experiments with cannons that led him to conclude that thermal energy (heat) and mechanical energy were related. He noticed that the temperature of water increased significantly when the cannon barrel was continuously drilled, indicating that the mechanical work being done on the cannon increased the water's temperature.
As for evidence contradicting the idea that heat was a fluid, James Prescott Joule's experiments helped establish that heat is a form of energy and not a substance. Joule's research on the mechanical equivalent of heat showed that work could transfer energy into or out of a system, demonstrating that heat is a form of energy and not a fluid.