Complex sentence: Bull planned to make a sealing and whaling voyage into Antarctic waters; after failing to interest Melbourne's learned societies in a cost-sharing venture of a commercial--scientific nature, he returned to Norway to organise his expedition there.
Split into simpler sentences: Bull planned to make a sealing and whaling voyage into Antarctic waters. After failing to interest Melbourne's learned societies in a cost-sharing venture of a commercial--scientific nature, he returned to Norway to organise his expedition there.