The Plunger-Filled Fountain Pen: A Measured Dose of Ink per Stroke

"The manner of filling and using, is as follows: when the pen is to be filled, the plunger is drawn back by the thumb and finger, hold of the nut D, which allows the ink to fall from the reservoir B, into the filling tube H. The plunger is then suddenly returned, which forces the ink in said tube into the barrel of the pen, through the aperture K, said plunger forming a perfect stopper in said tube which prevents the escape of the ink until another supply for the pen is required." "Felting, or woolen cloth, will probably answer in the room of sponge, for the purpose of the stopper, as its office is to check the flow of the ink through the aperture K, except under the pressure of the piston as before stated."

**Reservoir.** Cut 5 cm of clear acrylic tube as the reservoir and seal a disc of rubber sheet across its lower end with a hole in the middle. **Filling tube and plunger.** Take a Luer syringe: its barrel is the filling tube, its plunger the piston. Cut a side port in the barrel near its top with the craft knife, below where the plunger sits when drawn back, and seal the reservoir's hole over that port with epoxy, so ink falls in when the plunger is drawn back. **Stopper and nib.** Push a plug of sponge into the syringe's nozzle and fit a dip-pen nib against it. **Test.** Fill the reservoir with ink. Draw the plunger back past the port, wait a moment, and push it home once. Weigh the assembly before and after with the kitchen scale; 1 g of ink is about 1 ml. Do ten strokes and compare the spread with a free squeeze of a syringe. Then write with the nib until it runs dry, and count the words.

**Walter Hunt** of New York signed US 4,927 on 12 September 1845; it is dated 13 January 1847. His plunger was india rubber, or leather saturated with india-rubber paste, on a wire piston rod through a stuffing box; a band with a crescent opening held the pen, and a sliding holder let the pen be drawn back and shielded for the pocket. His claim is the filling tube of graduated capacity combined with the fountain pen. The same Walter Hunt patented the float inkstand in 1845 and later the safety pin. **Honest limits.** A Luer syringe and an acrylic tube stand in for his shaft, reservoir and plunger. The notebook uses his printed sizes, taking the bulb as a cylinder. Your dose weighings are the result.