Lewis Waterman Did Not Invent the Fountain Pen. He Invented the Small Part That Stopped It Blotting.

US293545 was granted to L. E. Waterman on February 12, 1884. The Patent Office title is Fountain-Pen. The pen was not new. The part of it that Waterman fixed had been defeating inventors for half a century.

The problem with every fountain pen before this

A fountain pen is a reservoir of ink, a nib, and a path between them. The difficulty is entirely in that path, and it comes down to a fact about closed containers.

When ink leaves the reservoir, something has to take its place. If air cannot get in, a vacuum forms behind the ink and the flow stops, and the pen writes dry. If air can get in freely, it tends to arrive all at once as a bubble, which shoves a slug of ink out through the nib and deposits a blot on the page.

Early fountain pens swung between these two failures, sometimes within the same sentence. They were widely sold and widely disliked. Many people kept using dip pens, which are inconvenient but predictable.

The trouble was never the reservoir or the nib. It was that ink going out and air coming in were fighting over the same passage.

What the patent does

Waterman's answer was to cut a series of narrow grooves, or fissures, into the hard rubber feed bar that sits between the reservoir and the nib.

These channels are fine enough for capillary action to take hold. Ink wets the walls of a narrow channel and is drawn along it steadily, and the narrowness means the flow is metered rather than free. The pen delivers a controlled trickle instead of a surge.

The clever part is what happens in the same grooves at the same time. Because a groove is a channel rather than a sealed tube, air can travel back up along it, past the ink, into the reservoir. Ink moves forward and air moves backward in the same passage, continuously, and the pressure inside the reservoir never gets far enough out of balance to either lock the flow or force a blob out.

It is a small piece of shaped rubber. It is also the difference between a pen you can carry in a pocket and a device that ruins documents.

The story about the contract

The tale attached to this patent is well known. Waterman is said to have been an insurance salesman who had a client ready to sign a policy, produced a fountain pen for the signature, and watched it blot ink across the contract. By the time he returned with a replacement form, a competitor had signed the client instead. He is said to have gone away and built a better pen.

The story is repeated in nearly every account of the company, and it is a very good story. It is also the kind of origin tale that later company advertising tends to polish, and the evidence for it is thin. Treat it as a legend that may well contain something true rather than as a documented event.

What is documented is that Waterman was selling pens in New York in the 1880s, initially assembling them by hand and selling them out of a cigar shop, and that he backed them with a guarantee at a time when buyers had every reason to distrust a fountain pen.

Afterward

The company he founded became one of the dominant pen makers in the world. Waterman died in 1901, and the business carried his name long after.

The feed design spread and improved, and by the early twentieth century the fountain pen had become the ordinary tool of business and correspondence, which it remained for roughly fifty years until a different pressure-and-flow solution arrived and displaced it. That one used a rotating ball, and it is covered in our story on the ballpoint pen.

Waterman's contribution is easy to undervalue because it is not the visible part of the object. Nobody buys a pen for its feed. The nib gets the attention, the barrel carries the brand, and the grooved piece of rubber in the middle is the reason any of it works.

See the original

The full text and figures of US293545 are on patents.us.