South-Southeast

South-southeast is a bearing of 157.5 degrees, midway between south and southeast. The naming convention for the sixteen- and thirty-two-point rose is systematic: the four cardinals, then the four intercardinals named by combining them, then the eight secondary intercardinals named by prefixing the nearer cardinal, and finally, in the thirty-two-point rose, sixteen further points named by the formula north by east, northeast by north and so on. The order is fixed and the names are not interchangeable, so south-southeast and southeast by south are different bearings eleven and a quarter degrees apart. The system is entirely a navigational and surveying convention. Cosmological schemes that use more than eight directions, such as the Chinese twenty-four mountains or the ten directions of Buddhist cosmology, divide the circle differently and do not map onto it.

South-southeast is one of the thirty-two points of the traditional mariner's compass rose, bisecting south and southeast at 157.5 degrees. Each of the thirty-two points carries a formal compound name built by a fixed grammar, a cardinal-intercardinal point such as south-southeast names the half-way bearing between its two named neighbours by combining them in a set order, cardinal direction first, and the whole naming system was standardised for English-language navigation by the eighteenth century as the reference against which magnetic compass headings, and later the fully numerical 360-degree bearing system now standard in aviation and modern navigation, were taught and cross-checked by mariners memorising the full thirty-two-point rose.

South-southeast, at 157.5 degrees, falls on the boundary between the mountain Si, the branch of the snake, and the mountain Bing, a heavenly stem lying just east of due south.

The luopan divides the horizon into twenty-four mountains of fifteen degrees, drawn from the twelve earthly branches, eight of the ten heavenly stems, and the four trigrams that occupy the corners. The European compass rose divides it by repeated halving into eight, sixteen and thirty-two points. The two schemes meet at eight places and diverge everywhere else, and each secondary point of the sixteen-point rose lands on a seam between two mountains.

Due south itself is the mountain Wu, the branch of the horse, and it carries more weight in Chinese orientation than any other bearing, since south is the direction a ruler faces and the direction a hall is conventionally oriented toward. Bing and Ding, the two stems flanking Wu, therefore sit in the most closely watched arc of the whole ring, and the fifteen-degree distinction between them and the horse is not a technicality in the compass schools.

Si, the snake, is the double hour from nine to eleven in the morning, and in the cycle of months it belongs to the fourth. As with every mountain, the character carries a direction, an hour and a season together, which is what allows a luopan reading to be cross-checked against a date.