1000 Geared astrolabe of al-Biruni

EUROPE

1000 Gerbert astronomical model

ISLAM

1025 Equatorium text

CHINA

1074 Shen Kua, clocks and magnetic compass
1080 Su Sung clock built
1101 Su Sung clock destroyed

INDIA

1100 (_ca._) S[=u]rya Siddh[=a]nta animated astronomical models
and perpetual motion
1150 (_ca._) Siddh[=a]nta Siromani animated models and perpetual
motion

ISLAM

1150 Saladin clock

EUROPE

1187 Neckham on compass
1198 Jocelin on water clock

ISLAM

1200 (_ca._) Ri[d.]w[=a]n water-clocks, perpetual motion
and weight drive
1206 al-Jazar[=i] clocks, etc.
1221 Geared astrolabe
1232 Charlemagne clock
1243 al-Konbas (compass)

EUROPE

1245 Villard clocktower, "escapement," perpetual motion
1267 Villers Abbey clock
1269 Peregrinus, compass and perpetual motion
1271 Robertus Anglicus, animated models and "perpetual motion" clock

ISLAM

1272 Alfonsine corpus clock with mercury drum, equatoria

EUROPE

1285 Drover's water clock with wheel and weight drive
1300 (_ca._) French geared astrolabe
1320 Richard of Wallingford astronomical clock and equatorium
1364 de Dondi's astronomical clock with mechanical escapement
later 14th C. Tradition of escapement clocks continues
and degenerates into simple time-keepers
------------------------------------------------------------------------

There is therefore reasonable grounds for supporting the medieval
European tradition that the magnetic compass had first come from China,
though one cannot well admit that the first news of it was brought, as
the legend states, by Marco Polo, when he returned home in 1260. There
might well have been another wave of interest, giving the impetus to
Peter Peregrinus at this time, but an earlier transmission, perhaps
along the silk road or by travelers in crusades, must be postulated to
account for the evidence in Europe, _ca._ 1200. The earlier influx does
not play any great part in our main story; it arrived in Europe before
the transmission of astronomy from Islam had got under way sufficiently
to make protoclocks a subject of interest. For a second transmission, we
have already seen how the relevant texts seem to cluster, in France
_ca._ 1270, around a complex in which the protoclocks seem combined with
the ideas of perpetual motion wheels and with new information about the
magnetic compass.