Mongolian Ba ᠪ

Ba writes the voiced bilabial stop, the sound made by closing both lips and releasing them with the voice on, and it is the tenth letter of the alphabet. It is one of the most straightforward letters here: the sound is common, native, unrestricted in position, and distinctly written. Unicode encodes it at U+182A. Its form is worth attention because it shows how the script hangs together. Traditional Mongolian is written in vertical columns, and every letter of a word attaches to a continuous vertical spine running down the middle of the column.

A word is therefore a single connected object rather than a row of separate signs, and each letter is a set of strokes departing from that spine and returning to it. The bilabial stop is drawn as a bowl or hook off the spine, closed at the point where the next letter continues downward. Because the spine is continuous, the shape a letter takes depends on what has to happen before and after it, which is the practical reason for the three positional forms every letter carries. Writing this script is closer to writing a joined European hand than to setting separate types, and the calligraphic tradition that grew around it treats a word as one gesture.

The most immediately visible fact about traditional Mongolian is that it runs down the page rather than across it, and that its columns are ordered from left to right. Both halves of that matter. Vertical writing is not unusual in itself, since Chinese, Japanese and Korean have all been written in columns, but those columns run from right to left, and Mongolian runs the other way. The direction is inherited rather than chosen. The alphabet came from Old Uyghur, which was written horizontally from right to left in the manner of its Aramaic ancestry, and was rotated a quarter turn counterclockwise to be written in columns, which turns a right to left line into a top to bottom one and leaves the columns advancing to the right.

A script's direction is one of the most conservative things about it, and this one preserves the evidence of two earlier arrangements at once. There are practical consequences. A Mongolian text sits awkwardly in a horizontal page layout and awkwardly on a screen, which is one reason digital support took a long time to mature. Bilingual signage in Inner Mongolia, where the script is in continuous everyday use, characteristically pairs vertical Mongolian with horizontal Chinese, and the two occupy the same sign in quite different ways.