31. About focusing : See curved mirror-a perfectly focusing mirror is actually paraboloid , not spherical. 32. The "'flux density is increased "'near the edge of the paraboloid . 33. The circular paraboloid that collects sound waves and directs those waves towards the owl's ears. 34. This allows us to use a paraboloid frustum where that form appears more appropriate than a cone. 35. Strictly, the three-dimensional shape of the reflector is called a " paraboloid ". 36. The rotation shapes them into paraboloids that are accurate enough to be used as primary reflectors in telescopes. 37. Unusually for a radio telescope, the primary reflector is an off-axis segment of a paraboloid . 38. The paraboloid focuses through a central hole in the feed flat to a convenient distance behind the flat. 39. Other interesting structures that he designed included the shells ( hyperbolic paraboloid ) for the Cairo International Fair. 40. The GPO antenna at Goonhilly Downs in Great Britain was a conventional 26-meter-diameter paraboloid .
