Abstract: This invention relates to a high-yield methane production process, comprising cultivating on a culture medium containing a source of nitrogen and assimilable salts, the methanogenic bacterium Methanobacterium thermoautotrophicum or any other methanogenic bacterium having the same physiological growth properties, with a forced supply of gaseous H.sub.2 /CO.sub.2 mixture.

Abstract: Protection glasses comprise a screen which is at least partially transparent and that has upper and lower substantially horiziontal edges. At least one movable wiping member wipingly engages at least one face of the screen and slidably engages the upper and lower edges of the screen thereby releasably to retain the wiping member in horizontal sliding engagement with the screen. The screen preferably has at least one flange along at least one of its edges to mount the wiping member. The wiping member can be in the form of a single member that embraces the screen to wipe both sides of the screen, or two members slidable on flanges along both edges of the screen. The screen can be integral with the frame of the glasses.