The development of the submarine weapon was a product of many different minds, all with varying intentions. Some were patriots, seeking the ultimate counter to the naval super-weapons of first-rate powers. Others were schemers, betting their lives and fortunes on unproven vessels of their own design, seeking riches and renown beyond measure. There were, of course, those who explored the physical universe through the mind, men who could conceptualize the vastly complicated interaction of man-made materials and the physical nature of the abyss. These men oftentimes never sought to bring their drawings and writings from the confine of paper or parchment, but inspired generations of dreamers to follow. The most important group, however, was that of the journeyman inventor, men of the mind who traveled from country to country seeking patronage for their radical dreams.
The next few decades enabled many important advances in metallurgy, steam power and advancements of knowledge in the physical world. Unfortunately, these individual industrial and scientific victories did not translate into the development of a working submarine. In 1831, Spanish inventor Cervo attempted to demonstrate his spherical submarine to publishers. He disappeared on the first dive. Three years later, French physician Petit of Amiens tested a similarly designed submarine in the St. Valery sur Somme. His body was found as the tide receded, drowned inside his flooded craft. In 1851, American shoemaker Lodner D. Phillips was ostensibly more successful with his inventions—two 40-foot submarines, both designed in the now-classic cigar shape, but with conical ends. Still powered by hand-operated propellers, he did develop manually operated ballast tanks. One of two submarines was outfitted for civilian use, primarily limited underwater survey. This submarine was successfully used to explore the bottom of Lake Michigan under the tense supervision of large crowds of curiosity-seekers. He even equipped the civilian version of the submarine with a few crude tools, one of which was even able to saw through a 14-inch timber of submerged wood. The military version had a decidedly more pointed purpose, and was equipped with an underwater gunpowder mine. His underwater voyages became a family affair, as his wife and children often accompanied him on surveys, tests and demonstrations. Eventually, he moved his experiments to Lake Erie, but his luck ran out, and he disappeared with his handmade submarine.