So you dont have to guess next time on how tight the cone should be:

tighten the cones down go all the way till the axle doesn't move very freely. Now back up the cone just a touch so that the axle does move freely. The object is to get the cones at tight as you can without effecting the purpose of the bearings which is to let the axle spin freely.

If the cones are too tight then the axle doesn't move(and you damage your races and cones)
if the cones are too loose then you will have lateral axle play(and a wobbly ride, unsure braking etc)
it is all about getting it just perfect for the best ride quality and to prolong your hub life