Answer:
The Sandwich Islands were named in the 1770's by James Cook and are known today as the Hawaiian Islands. Other islands in the Pacific which have at some time been known as Sandwich Island are Manuae in the Cook Islands and Efate in Vanuatu.
Tonga was known as the Friendly Islands because of the reception once given to James Cook.
If you are interested in the history of the Pacific Islands written in Victorian times you may be interested in 'The History of Mankind' by Prof. F Ratzel (see associated link).