Decades: 1340s 1350s 1360s 1370s 1380s - 1390s - 1400s 1410s 1420s 1430s 1440s
Years: 1390 1391 1392 1393 1394 - 1395 - 1396 1397 1398 1399 1400
Births
Deaths
... the groove must not be lubricated. The acceleration of the gyroscope is best when the precession of the gyroscope is supported and amplified by wrist motion. I ...