Ancient Knowhow at Dendera The image below is taken from an ACAD drawing using the Pinterest.com image as the background picture from what has sometimes been dubbed the Ancient Egyptian Light Bulb. If one goes to Wikipedia “Crookes tube” you will find that the Crookes Tube operated at a substantial vacuum, meaning the small glass bulb had to withstand the sea level vacuum of 14.7 psia. For a glass tube of about inch in diameter and short enough to be hand held, the collapsing force would be representative of a few gallons of milk. Given in the image above that the standing men are about six feet tall, the so-called bulb would be near 8 feet in length and perhaps a couple feet in width at the widest point. That would approximate the Crookes Tube collapsing force at over 33,000 pounds. In dust evacuating steel ductwork operating only at the vacuum levels created by a kid sucking on a soda straw, there needs to be stiffeners roughly every diameter in length. Negati