The armillary sphere was the most important astronomical observation apparatus in ancient China . In the shape of a 
celestial globe seen by the man , it consisted of multi-layer concentric rings . On the outer layer were two rings of a similar size , fixed together and mutually perpendicular . One ring was called celestial latitude ring , parallel to the plane of the celestial equator . The other ring was vertical to it and was called the meridian ring . On the two rings were carved graduations and directions . On the celestial latitude ring plane was a revolving peeping hole . Turning the celestial latitude ring and the revolving peeping hole , one could aim the peeping hole at any point in the heaven and determine the coordinates of this point on the celestial latitudes and celestial longitudes . At 323 B.C. Kong Ting , and official historian of the Zhao Kingdom , made the first armillary sphere . With the aid of the armillary sphere , the ancient Chinese found out the coordinates of the movements of the sun and the moon and other important stars with a very high precision .
Later astronomers improved on the armillary sphere to meet various practical needs . Guo Shoujin , a scientist into the simplified armillary spheres , and raised the level of astronomical observation in China several centuries ahead of the rest of the world .
The principle of its equatorial system is the same as that of the modern equatorial telescope. Even their external 
shapes are very similar . Traditionally , western astronomers used the ecliptic coordinates , based on the plane of the orbit of the revolution of the earth around the sun , which has an included angle of 23’’27’ . Only at the end of the 16th century , a prominent Danish astronomer began to use the equatorial astronomical observation apparatus . It has been considered as an important progress in European astronomy during the Renaissance , but it was later than Guo Shoujin’s simplified armillary sphere by three centuries .
A ceramic model ship in the Eastern Han Dynasty was unearthed in ceramic modern ship in the 
Eastern Han Dynasty was unearthed in Guangzhou . An axial rudder was found at its stern . It was transitional from the long oar rudder to the axial turning rudder . Between the second and fourth centuries A.D. , the true axial turning rudder was used already in China , which was important for raising ship-operating efficiency . In about the twelfth century A.D. both the water-tight compartments and the axial turning rudder spread westward to the Mediterranean via the Indian Ocean . In the eleventh century A. D. the Chinese already invented the balance rudder and the holed rudder , both of which were only found in Europe at the eighteenth century A.D.
Guo Shoujin was very ingenious in simplifying the armillary sphere . All the later astronomical researches have recoursed on the ingenuity of his equatorial astronomical observation apparatus .
Embryo of gas turbine
The running horse lantern was an ancient Chinese thermodynamic product appearing in the Song 
Dynasty .The structure of it is very simple . It has a middle shaft , on the top of which is a horizontal vane wheel . Under he vane wheel near the shaft was installed a candle base . After the candle was ignited , the ascending ho air drives the vane wheel to revolve . Also on the middle of the shaft are tied four wires horizontally , on which stand paper horses and paper men . In the night , when the shadows of them are projected to the shell paper of lantern , hey look as if they are running quickly . The ingenuity of the running horse lantern lies in that it makes the fire in the lantern a source of dynamic power in addition to lighting . Though the running horse lantern was used then only as a toy , yet it was the embryo of a simple gas turbine . Besides , Joseph Needham reckoned that the running horse lantern demonstrated that the Chinese were the first to know the principle of cinema.
