We have to anticipate what some of the costs are going to be.

Each year we have students that come back because they say it is less expensive.

The increase in petroleum also causes it to be more expensive to actually produce the food and things of that nature.

The plane is simply abstracting the power stored in the wave by a distant gale, and using it to counteract gravity. And if the work be continued long enough, or a multitude of planes be continually drawing on the reservoir of power, the wave must inevitably be flattened.

As to the effect of the wave on the air, we will suppose the water to be quite flat and the air motionless, a heavy undulation comes on the scene, it has to pass, so it pushes the air up with its face, letting it fall again as its back glides onwards.

Used as kites, these rigid stable aeroplanes are superior to the very best cellular kites I can make; they are lighter, pull harder per square foot, attain a greater angle of elevation, and have fewer parts.