From the Sung Shu

written around 500:

The south-pointing carriage was first constructed by the Duke of Chou (beginning of the -1st millennium) as a means of conducting homewards certain envoys who had arrived from a great distance beyond the frontiers. The country to be traversed was a boundless plain, in which people lost their bearings as to east and west, so (the Duke) caused this vehicle to be made in order that the ambassadors should be able to distinguish north and south.

The Kuei Ku Tzu book says that the people of the State of Chêng, when collecting jade, always carried with them a `south-pointer', and by means of this were never in doubt (as to their position).

During the Chhin and Former Han dynasties, however, nothing more was heard of the vehicle. In the Later Han period, Chang Hêng re-invented it, but owing to the confusion and turmoil at the close of the dynasty it was not preserved.

In the State of Wei (in the San Kuo period) Kaothang Lung and Chhin Lang were both famous scholars; they disputed about the south-pointing carriage before the court, saying that there was no such thing, and that the story was nonsense. But during the Chhing-Lung reign-period (+233 to +237) the emperor Ming Ti commissioned the scholar Ma Chün to construct one, and he duly succeeded. This again was lost during the troubles attending the establishment of the Chin dynasty.

Later on, Shih Hu (emperor of the Hunnish Later Chao dynasty) had one made by Hsieh Fei; and again Linghu Shêng made one for Yao Hsing (emperor of the (Chiang) Later Chhin dynasty). The latter was obtained by emperor An Ti of the Chin in the 13th year of the I-Hsi reign-period (+417), and it finally came into the hands of emperor Wu Ti of the (Liu) Sung dynasty when he took over the administration of Chhang-an. Its appearance and construction was like that of a drum-carriage (hodometer). A wooden figure of a man was placed at the top, with its arm raised and pointing to the south, (and the mechanism was arranged in such a way that) although the carriage turned round and round, the pointer-arm still indicated the south. In State processions, the south-pointing carriage led the way, accompanied by the imperial bodyguard.

These vehicles, constructed as they had been by barbarian workmen, did not function particularly well. Though called south-pointing carriages, they very often did not point true, and had to negotiate curves step by step, with the help of someone inside to adjust the machinery.

That ingenious man from Fanyang, Tsu Chhung-Chih, frequently said, therefore, that a new (and properly automatic) south-pointing carriage ought to be constructed. So towards the close of the Shêng-Ming reign-period (+477 to +479) the emperor Shun Ti, during the premiership of the Prince of Chhi, commissioned (Tsu) to make one, and when it was completed it was tested by Wang Sêng-Chhien, military governor of Tanyang, and Liu Hsiu, president of the Board of Censors. The workmanship was excellent, and although the carriage was twisted and turned in a hundred directions, the hand never failed to point to the south.

Under the Chin, moreover, there had also been a south-pointing ship.

The pigtailed barbarian Thopa Tao (third emperor of the Northern Wei dynasty) caused a south-pointing carriage to be constructed by an artificer called Kuo Shan-Ming, but after a year it was still not finished. (At the same time) there was a man from Fu-fêng, Ma Yo, who succeeded in making one, but when it was ready he was poisoned by Kuo Shan-Ming.

Source: Needham. Joseph: Science and Civilization in China, Volume 4, Part II, 1965