Skim mode allows you to scan through thumbnail images of each page of the current chapter and jump to a desired page. To enter skim mode for the current chapter, click on the Skim button on the right side of the navigation bar. If you don't see this button, you may need to increase the width of your browser window. A popup will open showing thumbnail images of the pages of the current chapter, with the current page being shown in the center of the view. You may use your keyboard’s arrow keys, drag the slider bar, or use any left-right mouse scrolling functionality to scan through the thumbnail images.
When you find the image of the desired page, click on that thumbnail image and you will be taken directly to that page. If you would like to remain on the current page, click anywhere outside of the skim-mode popup window.