Thank you Mandy for the link.

Excellent information. Poor, poor elephant.
The extra information about Gray is quite interesting too. They did well for themselves didn't they?

Now why did JA mention the zoo (visited by the Dashwood family) and Gray, visited by the brother, sister, and brother in law of the brother.

The zoo, because they liked to see animals in captivity in small cages, or helpless???

Gray's, because I think to show that the brother shops at this expensive place (inspite of money problems ;) and Elinor visited because of money problems, I presume.
Elinor can expect to get good price for her mother's jewellery, while John Dashwood can boast about the good price he paid to buy the seal at Gray's.