Google Books provides online access to full text of public domain and out-of-copyright books, reproduced either from text provided by publishers or by the libraries.
Hathi Trust Digital Library is a digital preservation repository and access platform. Temple users have access to HathiTrust items that are in the public domain.
The Internet Archive's Open Library has digital copies of many books that can be borrowed. Only one person can use a title at a time. You need to create an Open Library account.