Here's the breakdown:
* Professor Porter (Jane's father), a renowned zoologist, is hired by a wealthy American businessman to explore the unexplored regions of Africa.
* Professor Porter and Jane embark on a ship voyage to reach the African coast.
* Clayton, who is introduced as a "hunter" and later becomes the antagonist, is not initially part of the expedition. He joins them later, initially appearing as a charming and knowledgeable companion.
* The ship is wrecked during a storm, leaving the survivors stranded in the jungle.
It's important to note that the movie adaptations often take creative liberties with the story, sometimes changing the mode of transportation or the circumstances of their arrival. For example, in the 1999 Disney movie, Jane and her father are traveling by hot air balloon.
So, the most accurate answer to your question, based on the original novel, is that Jane Porter and her father reached the jungle by steamship and subsequent shipwreck.