Scroll #8 is located in the room named Deep Down, located underneath the Maglev room. It depicts the rapid growth of Teslagrad with The King and Solomon Tesla looking on in approval. Faradeus flies in the background.
Normal Collection Method
After acquiring the Blink Boots, return to the Maglev room and drop into the hole in the floor, then blink left to reach Deep Down. Go up to the next floor by using the Power Plant, grab the scroll, and press the plunger to turn off the electric barrier blocking your way out.
Speedrun Collection Method
No special tricks here. Just constant blinking so you move at top speed.