Pete Smith’s narration is enjoyable, and in this instance, his delivery reaches a point of almost mocking amusement as he attempts to describe the scientific principles behind the new slow motion stroboscope—or “flicker box.” This device uses light that flashes up to 2000 times per second to aid in achieving sharp focus when altering the speed of action photography. The effect is well demonstrated, for example, when a golf ball strikes a phone book, a cat drinks milk, and we observe how accurately a pencil pierces the delicate surface of a bubble before witnessing the striking visual of a bullet’s trajectory from a gun barrel to a glass light bulb's destruction. These details are invisible to the unaided eye but appear with remarkable clarity. The presentation feels somewhat drawn out, though, as the imagery starts to feel repetitive—particularly involving milk and hummingbirds—and the ending scene set in a dentist’s chair pushes slow motion (along with its sound) perhaps too far for those who are easily bothered by it. If science lessons were presented with this same friendly tone, perhaps more of it would stick! It's generally an entertaining experience.

Source on TMDB