Ramps have been reported as being widely used in Ancient Egypt. A ramp is an inclined plane, or a plane surface set at an angle (other than a right angle) against a horizontal surface. The inclined plane permits one to overcome a large resistance by applying a relatively small force through a longer distance than the load is to be raised. In civil engineering the slope (ratio of rise/run) is often referred to as a grade or gradient. An inclined plane is one of the commonly-recognized simple machines. Maureen Clemmons subsequently led a team of researchers demonstrating a kite made of natural material and reinforced with shellac (which according to their research pulled with 97% the efficiency of nylon), in a 9 mph wind, would easily pull an average 2-ton pyramid stone up the 1st two courses of a pyramid (in collaboration with Cal Poly, Pomona, on a 53-stone pyramid built in Rosamond, CA).