If the battery is good, then it sounds as if the starter is dead. If you ran a jumper cable from the battery to the post on the starter then the starter should engage.

Typically, the solenoid is between the battery and starter. There's a small wire coming from the key switch. When the key is turned, that wire gets hot, closes the contacts on the solenoid, and completes the circuit between battery and starter.

Its pretty simple and you bypassed that so it sounds like weak battery or dead starter.