But Rex Raynor seemed to find nothing comical in the wind bird. Her slow progress while being dragged to the brow of Hogback Hill gave him a chance to study her every line. To an aviator used to the exquisite finish and polish of a modern factory-built sky boat, Hal's contraption offered a contrast of a rather sketchy aircraft fuselage. A little board, an upright post, some slim sprucewood longerons,--that was the fuselage, if one could call it a fuselage! But for all its homemade roughness, there was an interesting compactness in the way the boy had braced his few wires and uprights down to a "V," converging at the board seat. The one wing was a long cloth-covered affair of wood strips and wires--streamlined after a fashion, for it was narrower at the tips than in the center, and thinner at the back edge than at the front edge. The longerons ended in rudimentary elevators and rudder, connected by wires to a pair of pedals set before the board seat that was fastened at the nose of the fuselage. A broomstick control stuck up before the seat too, and wires hitched it to the wings.