Automatic Slideshow, Delay before Slide Advances
http://pptheaven.mvps.org/tutorials/SlideDelay.html

Tohlz, Shawn
PowerPoint Heaven
2005

Abstract:

You are making a slide show which runs automatically throughout your presentation without the needs of mouse clicking or entering of keyboard. The automatic slideshow can be photographs presentations and etc. In every slide, you realize that the slide advances to another slide immediately after the last animation ends. The result? Audience does not have the chance to read your slides because it moves too quickly. You will need to make some delay so that all your slides will pause for a while before going to the next one. There are few ways to achieve this. This tutorial will cover two simple methods.