Avrodamo is correct. I can't explain it any better. However, Gin Slinger is incorrect when he says that horizontal axis gyros can't topple. It is true that vertical axis gyros can't drift - they can only topple, but horizontal axis gyros can both topple and drift.
After all, if you take a vertical axis gyro and topple it 90 degrees, it is now in effect a horizontal axis gyro. However, it won't stop toppling, it will keep going, eventually passing the position it was orginally in. Hence logically a horizontal axis gyro can topple.
As Avrodamo correctly pointed out though, a horizontal axis gyro at the equator aligned North-South will not topple, but it is worth pointing out, if the same gyro was aligned east-west, it would topple.
Quick summary then:
Vertical axis gyros:
Pole: No drift and no topple
Equator: No drift and maximum topple
Horizontal axis gyros:
Pole: Maximum drift and no topple
Equator: (aligned North-South) No drift and no topple
(aligned East-West) No drift and maximum topple
TB