Most of the Library's e-book collection can be downloaded by chapter, section or page.  These books are in PDF format. Here is an example of a book in PDF format: PDF e-book from the Knovel Collection

We have a small collection of e-books that can be downloaded in their entirety to read offline.  These EBSCO E-books are in ePub format.  Before you can download/checkout books from EBSCO, you'll install Adobe Digital Collections to your computer or device (or Bluefire Reader if you have an Apple device) and create a free account with EBSCO.  Here is an example of a downloadable e-book from EBSCO: ePub book from the EBSCO E-book Collection

Go to the device list under "Reading with a Mobile Device" below for more information about using your mobile device. 

Refer to this list of E-book collections for more information about reading and downloading the Library's e-books.