Consider the following statements about the Indian Councils Act of 1861:

1. The Act introduced the principle of representative institutions by allowing non-official members in legislative councils.
2. It established the office of the Viceroy to replace the Governor-General.
3. The Act restored legislative powers to the provincial governments, marking the beginning of decentralization.
4. It introduced the concept of Dyarchy in provincial governance.

Which of the statements are correct?