Abstract: An all season window includes a rectilinear peripherally extending pane mounting frame. Three panes of transparent material are secured sealingly within the frame in parallel spaced relationship and extend vertically. A solar heat ray absorbent material is contained within the frame. In one preferred form of the invention the middle of the three panes comprises the solar heat ray absorbent material and a discrete amount of heat absorbent liquid is included within the frame. A pump and associated motor is provided for pumping the heat absorbent liquid between a first location in which it fills the region between the outer and intermediate panes and a second location in which the liquid fills the region between the inner and intermediate panes.

Abstract: An all season window includes a rectilinear peripherally extending pane mounting frame. Three panes of transparent material are secured sealingly within the frame in parallel spaced relationship and extend vertically. A solar heat ray absorbent material is contained within the frame. In one preferred form of the invention the solar heat ray absorbent material is a liquid. A pump and associated motor is provided for pumping the solar heat ray absorbent liquid between a first location in which it fills the region between the outer and intermediate panes and a second location in which the liquid fills the region between the inner and intermediate panes. In its described first location solar heat rays are absorbed by the liquid and a dead air space between the liquid and the closed environment sought to be provided with climatic control inhibits conduction of heat to such closed environment while the liquid conducts heat received thereby due to solar radiation through the outer pane to the outside environment.

Abstract: The invention resides in apparatus for directly measuring density altitude in an aircraft and includes a housing in communication with ambient conditions of air temperature, pressure and humidity outside the aircraft. A rotor having dynamically balanced blade elements is positioned rotatably within the housing. An electric motor is connected so as to drive the rotor within the housing against the resistance therein of the air under the ambient conditions of temperature, pressure and humidity. An operational characteristic of the motor, such as the current which it draws, is continuously sampled, amplified and changed in shape and applied as the input to a display device which is calibrated to display the input in terms of density altitude.