The simple search lets you search by keyword in full text, subject, or title, and set the time span of published volumes for your search. The search results will give you the volumes in which your search terms appear. Choosing a document will give you full bibliographic information, the option to search within the text, and, at the bottom of the page, the page numbers in which your search terms appears. Clicking on a page number gives you a page image. The journals section also has search, advanced search, and browse.
Simple search allows for a single keyword and a specified timeframe.
Mindbending amount of stuff here. Worth a look. The Free Library of Philadelphia has created an online exhibit of over 1,200 photographs and other materials related to the Centennial Exhibition of 1876 which took place in Philadelphia. There's a search engine for all the material on the site. Search results for photographs provide thumbnails and basic information.