Decades: 1200s 1210s 1220s 1230s 1240s - 1250s - 1260s 1270s 1280s 1290s 1300s
Years: 1246 1247 1248 1249 1250 - 1251 - 1252 1253 1254 1255 1256
Births
Deaths
... precessing, with its axis slipping around in the groove in a circular fashion. The groove inside the device, is a little wider than the axis, and the gyroscope's evasive ...