It was found impossible to make the Morse ink writer so sensitive that it could record signals sent over land lines of several hundred miles in length, if the speed of transmission was very much faster than that which could be effected by hand, and this led to the adoption of automatic methods of transmission.
But the material was also subject to other defects, such as moisture lurking between the layers, which might be detected by strokes of the mallet; spots or stains; and spongy strips (taeniae), in which the ink would run and spoil the sheet.
Buying fountain pen ink now-a-days is a little tricky.
The bull, so called from the leaden seal (bulla), is written on thick parchment; the special writing known as Lombard, which used to be used for bulls, was abolished by Leo XIII., and the leaden seal reserved for the more important letters; on the others it has been replaced by a rest ink stamp bearing both the emblems represented on the leaden seal: the two heads, face to face, of St Peter and St Paul, and the name of the reigning pope.
It was on plain white notepaper, lined and firmly creased, written somewhat shakily with an ink pen, in the dainty script of a woman.
It consisted of frayed reed pens or brushes, a small pot of water, and a palette with two circular cavities in which black and red ink were placed, made of finely powdered color solidified with gum.
Better to have the pen missing than to have the wrong color ink someone might notice.
When electric waves fell on the antenna they caused the mercury-steel junction to become conductive during the time they endured, and the siphon recorder therefore to write signals consisting of short or long deflexions of its pen and therefore notches of various length on the ink line drawn on the strip of telegraphic tape.
The armature acts on an inking disk on the principle described above, save only that the disk is supplied with ink from a groove in a second wheel, on which it rolls: the grooved wheel is kept turning with one edge in contact with ink in an ink-well.
The motion is first magnified by the lever, and, on its communication to a complex lever system above the stationary mass, is still further magnified before registration, which is effected by a pen supplied with ink writing on white paper.