The Archive file you download contains a TIFF image compressed into a ZIP archive.
Your browser may be already set up to decompress these files.
Commercial software to perform this is available from
PKWARE, Inc., the company that invented the format.
A web page from a group of people creating shareware or public
domain software is available at Info-ZIP.
The TIFFs are 150-dpi archival-quality color scans of the original forms and can be viewed by software like Corel PhotoPaint or Adobe PhotoShop.