Civil War cannonball drop towers

Embedded within the Alpha submarine arc as a Watertown Arsenal origin story. During the Civil War the Arsenal pursued a research program to drop molten cast iron from towers to form spherical cannonballs. Without knowledge of heat transfer or dimensionless numbers (chemical engineering wasn't invented until the 1880s, at MIT), they needed a ~50-mile-tall tower; surface-tension/gravity ratio also required drops below 3 mm. The program produced only splats. Tom uses it as a contrast to Watertown's eventual post-WWII success developing Ti-6Al-4V.

Right after World War II, titanium became available. Over at Watertown Arsenal, which is now Watertown Mall — the Army had an arsenal there since the 1860s. They used to try to make cannonballs at Watertown Arsenal for the Civil War. People knew that if you had small drops of metal and you melted them and let them fall to the ground, they solidified in the air and would be nearly pure spherical shape. So during the Civil War, they tried to build towers to drop molten cast iron for cannonballs and see if they would hit the ground and solidify. They didn't know a lot about heat transfer in the Civil War, and they realized the tower they had to have was about fifty miles tall to get the heat transfer. They also didn't know about the ratio of surface-tension forces to gravity forces — they would get ellipses and not spheres. The surface-tension forces have to dominate, and that's only below about three millimeters in size. But they didn't know about dimensionless numbers, and chemical engineering had not yet been invented.