I picked up an old fountain pen at a vintage bookstore this weekend for $5. It didn’t seem to have anything obviously wrong with it, but I couldn’t quite figure out how to fill it. Eventually I gathered that you click a button on the end of the reservoir area while the pen nib is in the ink bottle. But I couldn’t figure out whether you were supposed to click the button multiple times in rapid succession, or press and hold the button. I needed to test how much ink the pen would hold with each method, which involved writing the same text over and over and counting how many times I could write it with each fill. Given the colour of the ink, the choice of what words to write was obvious. ;)