Abstract: A continuous graphical display of barometric data includes an electronic trace of barometric pressure across a display in which the display including the trace, grid and axis labels are scrolled horizontally, with the display being updated from stored data on a continuous basis so that an entire week of uninterrupted barometric data can be presented, with preceding data being dropped off in a first in, first out scroll. Additionally a temporal history of temperature may be displayed as an electronic trace.

Abstract: A closed-circuit breathing apparatus includes an oxygen reservoir provided by flexible bags with open ends that can be rolled up and fastened in the rolled position to seal them. Oxygen is generated by a potassium superoxide canister that is activated by the water vapor in the exhaled breath of the user, and the oxygen generated is stored in the bag. The user breathes the oxygen from the bag, and flow of air through the system is controlled by simple check valves. Upward-directed passages are included in the air paths between a facemask and the check valves so that water droplets and ice are prevented from reaching the valves. The ice and water prevented from reaching the valves falls into a trap that can be easily cleaned in the field by removal of a plug.

Abstract: This disclosure teaches a screen such as those generally used for exhibiting projected images. A boxlike frame has a rim formed about its front. A membrane (the projection screen) covers the front with its margin extending to the vicinity of the rim. A cover encloses the back of the frame and is connected in sealed engagement to the margin of the membrane so as to form a plenum. Gas is withdrawn from the plenum whereby the membrane forms a concave image receiving surface curved in a relatively constant degree about a single point so that the image receiving surface takes on a spherical shape.

Abstract: A screen with characteristics of high brightness, controlled viewing angles, and ability to reject ambient light in which the longitudinal grooves formed therein are shaped so that the width and depth of each groove varies continuously along the length of the groove in a repeating sequence. The variation may take the form of a sine wave or be cuspoidal in shape.A method of producing the screen uses a rotating roller in which desired grooves are cut. After the drum is cut with a series of grooves, a molding material is placed around the drum and baked. After removing the molding material from the drum, it is turned inside out and copied. This copy is again copied and its result is electroformed and thus serves as a master roller for the screen of the present invention.