Speeding up Universal Viewer

Is there any way to speed up file load times in Universal Viewer? The installation I’m working on now has load times of 8-10 seconds between page images, which is just deadly given users’ expectations these days.: http://www.countypoorfarm.butlerhistorical.org/items/show/1#?c=0&m=0&s=0&cv=3&xywh=3463%2C1408%2C1845%2C2000

Or is this just a product of the image file sizes? The images in the “full size” directory are between 400-600 KB, and even those in the “originals” directory top out at 1.5 MB, neither of which seems unreasonable to me.

Appreciate any help!